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<ol class="chapter"><li class="chapter-item affix "><a href="../../index.html">Andrew's Blog</a></li><li class="chapter-item "><a href="../../posts/linux/linux.html"><strong aria-hidden="true">1.</strong> Linux</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/linux/install_linux.html"><strong aria-hidden="true">1.1.</strong> install linux</a></li><li class="chapter-item "><a href="../../posts/linux/bash_profile.html"><strong aria-hidden="true">1.2.</strong> bash profile</a></li><li class="chapter-item "><a href="../../posts/linux/command_list.html"><strong aria-hidden="true">1.3.</strong> command list</a></li><li class="chapter-item "><a href="../../posts/linux/git_guide.html"><strong aria-hidden="true">1.4.</strong> git guide</a></li><li class="chapter-item "><a href="../../posts/linux/tar.html"><strong aria-hidden="true">1.5.</strong> tar</a></li></ol></li><li class="chapter-item "><a href="../../posts/mac/mac.html"><strong aria-hidden="true">2.</strong> MacOS</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/mac/macos_profiles.html"><strong aria-hidden="true">2.1.</strong> macos profiles</a></li></ol></li><li class="chapter-item "><a href="../../posts/swift/swift.html"><strong aria-hidden="true">3.</strong> Swift</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/swift/learn_swift.html"><strong aria-hidden="true">3.1.</strong> learn swift basics</a></li><li class="chapter-item "><a href="../../posts/swift/swift_extensions.html"><strong aria-hidden="true">3.2.</strong> Swift extensions</a></li><li class="chapter-item "><a href="../../posts/swift/swiftui_extension.html"><strong aria-hidden="true">3.3.</strong> SwiftUI extensions</a></li><li class="chapter-item "><a href="../../posts/swift/install_swift.html"><strong aria-hidden="true">3.4.</strong> install swift</a></li><li class="chapter-item "><a href="../../posts/swift/task_planner.html"><strong aria-hidden="true">3.5.</strong> implment task panner app with SwiftUI</a></li><li class="chapter-item "><a href="../../posts/swift/swift_cheat_sheet.html"><strong aria-hidden="true">3.6.</strong> Swift Cheat Sheet</a></li><li class="chapter-item "><a href="../../posts/swift/yinci_url.html"><strong aria-hidden="true">3.7.</strong> Personal privacy protocol</a></li><li class="chapter-item "><a href="../../posts/swift/swift_regular_exressions.html"><strong aria-hidden="true">3.8.</strong> Swift regular exressions</a></li><li class="chapter-item "><a href="../../posts/ios/how_to_create_beautiful_ios_charts_in_swift.html"><strong aria-hidden="true">3.9.</strong> How to Create Beautiful iOS Charts in Swift</a></li><li class="chapter-item "><a href="../../posts/swift/swiftui_source_code.html"><strong aria-hidden="true">3.10.</strong> SwiftUI source code</a></li><li class="chapter-item "><a href="../../posts/swift/use_swift_fetch_iciba_api.html"><strong aria-hidden="true">3.11.</strong> use swift fetch iciba API</a></li></ol></li><li class="chapter-item "><a href="../../posts/ios/ios.html"><strong aria-hidden="true">4.</strong> iOS</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/ios/cocaposd_setup_and_install_for_ios_project.html"><strong aria-hidden="true">4.1.</strong> cocaposd setup and install for ios project</a></li><li class="chapter-item "><a href="../../posts/ios/swiftui_show_gif_image.html"><strong aria-hidden="true">4.2.</strong> SwiftUI show gif image</a></li><li class="chapter-item "><a href="../../posts/ios/implement_task_planner_app.html"><strong aria-hidden="true">4.3.</strong> implement Task planner App</a></li></ol></li><li class="chapter-item "><a href="../../posts/objective_c/objective_c.html"><strong aria-hidden="true">5.</strong> Objective-C</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/objective_c/objective_c_cheat_sheet.html"><strong aria-hidden="true">5.1.</strong> Objective-C Cheat Sheet</a></li><li class="chapter-item "><a href="../../posts/objective_c/objective_c_for_absolute_beginners_read_note.html"><strong aria-hidden="true">5.2.</strong> Objective-C Note</a></li></ol></li><li class="chapter-item expanded "><a href="../../posts/dart/dart.html"><strong aria-hidden="true">6.</strong> Dart</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/dart/flutter.html"><strong aria-hidden="true">6.1.</strong> Flutter Cheat Sheet</a></li><li class="chapter-item expanded "><a href="../../posts/dart/dart_cheat_sheet.html" class="active"><strong aria-hidden="true">6.2.</strong> Dart Cheat Sheet</a></li><li class="chapter-item "><a href="../../posts/flutter/flutter_dev_test.html"><strong aria-hidden="true">6.3.</strong> Flutter dev test</a></li></ol></li><li class="chapter-item "><a href="../../posts/rust/rust.html"><strong aria-hidden="true">7.</strong> Rust</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/rust/offline_use_rust.html"><strong aria-hidden="true">7.1.</strong> Offline use rust</a></li><li class="chapter-item "><a href="../../posts/rust/rust_grammer.html"><strong aria-hidden="true">7.2.</strong> rust grammar</a></li><li class="chapter-item "><a href="../../posts/rust/pase_string_and_decimal_conversion.html"><strong aria-hidden="true">7.3.</strong> pase string and decimal conversion</a></li><li class="chapter-item "><a href="../../posts/rust/parse_types.html"><strong aria-hidden="true">7.4.</strong> rust types</a></li><li class="chapter-item "><a href="../../posts/rust/rust_life_cycle.html"><strong aria-hidden="true">7.5.</strong> Rust life cycle</a></li><li class="chapter-item "><a href="../../posts/rust/rust_generic.html"><strong aria-hidden="true">7.6.</strong> rust generics</a></li><li class="chapter-item "><a href="../../posts/rust/rust_implment_matrix.html"><strong aria-hidden="true">7.7.</strong> Rust implement matrix</a></li><li class="chapter-item "><a href="../../posts/rust/rust_sort.html"><strong aria-hidden="true">7.8.</strong> Rust implement sort algorithms</a></li><li class="chapter-item "><a href="../../posts/rust/implement_aes_encryption.html"><strong aria-hidden="true">7.9.</strong> Rust implement AEC encryption and decryption</a></li><li class="chapter-item "><a href="../../posts/rust/implement_trie_data_structure.html"><strong aria-hidden="true">7.10.</strong> implement trie data structure</a></li><li class="chapter-item "><a href="../../posts/rust/rust_implement_tree.html"><strong aria-hidden="true">7.11.</strong> implement tree data_structure</a></li><li class="chapter-item "><a href="../../posts/rust/list_dir.html"><strong aria-hidden="true">7.12.</strong> list dir</a></li><li class="chapter-item "><a href="../../posts/rust/fast_way_to_implment_object_trait.html"><strong aria-hidden="true">7.13.</strong> fast way to implment object trait</a></li><li class="chapter-item "><a href="../../posts/rust/compress_rust_binary_size.html"><strong aria-hidden="true">7.14.</strong> compress rust binary size</a></li><li class="chapter-item "><a href="../../posts/rust/implment_file_upload_backend.html"><strong aria-hidden="true">7.15.</strong> impliment file upload</a></li><li class="chapter-item "><a href="../../posts/rust/this_is_add_post_cli_implementation_in_rust.html"><strong aria-hidden="true">7.16.</strong> this is add_post cli implementation in rust</a></li><li class="chapter-item "><a href="../../posts/rust/use_rust_implment_a_copyclipbord_cli.html"><strong aria-hidden="true">7.17.</strong> Use rust implment a copyclipbord CLI</a></li><li class="chapter-item "><a href="../../posts/rust/sqlite_database_add_delete_update_show_in_rust.html"><strong aria-hidden="true">7.18.</strong> sqlite database add delete update show in rust</a></li><li class="chapter-item "><a href="../../posts/rust/implementing_tokio_joinhandle_for_wasm.html"><strong aria-hidden="true">7.19.</strong> Implementing tokio JoinHandle for wasm</a></li><li class="chapter-item "><a href="../../posts/rust/rust_implement_a_crate_for_encode_and_decode_brainfuck_and_ook.html"><strong aria-hidden="true">7.20.</strong> rust implement a crate for encode and decode brainfuck and ook</a></li><li class="chapter-item "><a href="../../posts/rust/slint_builtin_elements.html"><strong aria-hidden="true">7.21.</strong> Slint Builtin Elements</a></li><li class="chapter-item "><a href="../../posts/rust/corporate_network_install_rust_on_windows.html"><strong aria-hidden="true">7.22.</strong> Corporate network install Rust on windows</a></li><li class="chapter-item "><a href="../../posts/rust/rust_binary_file_how_to_judge_static_link_or_dynamic_link_in_macos.html"><strong aria-hidden="true">7.23.</strong> rust binary file how to judge static link or dynamic link in Macos</a></li><li class="chapter-item "><a href="../../posts/rust/rust_binary_include_dir_and_get_contents.html"><strong aria-hidden="true">7.24.</strong> rust binary include dir and get contents</a></li><li class="chapter-item "><a href="../../posts/rust/how_to_create_yolov8_based_object_detection_web_service_using_python,_julia,_node.js,_javascript,_go_and_rust.html"><strong aria-hidden="true">7.25.</strong> How to create YOLOv8-based object detection web service using Python, Julia, Node.js, JavaScript, Go and Rust</a></li></ol></li><li class="chapter-item "><a href="../../posts/java/java.html"><strong aria-hidden="true">8.</strong> Java</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/java/java_grammar.html"><strong aria-hidden="true">8.1.</strong> java grammar and codewar</a></li><li class="chapter-item "><a href="../../posts/java/run_jar.html"><strong aria-hidden="true">8.2.</strong> java run .jar</a></li><li class="chapter-item "><a href="../../posts/java/java_pomxml_add_defaultgoal_to_build.html"><strong aria-hidden="true">8.3.</strong> Java pomxml add defaultGoal to build</a></li><li class="chapter-item "><a href="../../posts/java/java_set_mvn_mirror.html"><strong aria-hidden="true">8.4.</strong> Java set mvn mirror</a></li></ol></li><li class="chapter-item "><a href="../../posts/python/python.html"><strong aria-hidden="true">9.</strong> Python</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/python/convert_pesn.html"><strong aria-hidden="true">9.1.</strong> convert pesn</a></li><li class="chapter-item "><a href="../../posts/python/find_remove_dir.html"><strong aria-hidden="true">9.2.</strong> find and remove dir</a></li><li class="chapter-item "><a href="../../posts/python/timing_message.html"><strong aria-hidden="true">9.3.</strong> wechat send message</a></li><li class="chapter-item "><a href="../../posts/python/use_python_openpyxl_package_read_and_edit_excel_files.html"><strong aria-hidden="true">9.4.</strong> Use python openpyxl package read and edit excel files</a></li><li class="chapter-item "><a href="../../posts/python/sanctum_model_yaml.html"><strong aria-hidden="true">9.5.</strong> sanctum model yaml</a></li><li class="chapter-item "><a href="../../posts/python/how_to_detect_objects_on_images_using_the_yolov8_neural_network.html"><strong aria-hidden="true">9.6.</strong> How to detect objects on images using the YOLOv8 neural network</a></li></ol></li><li class="chapter-item "><a href="../../posts/go/go.html"><strong aria-hidden="true">10.</strong> Go</a></li><li class="chapter-item "><a href="../../posts/js/js.html"><strong aria-hidden="true">11.</strong> Javascript</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/js/js_tutorial.html"><strong aria-hidden="true">11.1.</strong> js tutorial</a></li><li class="chapter-item "><a href="../../posts/js/js_tutorial_map.html"><strong aria-hidden="true">11.2.</strong> ja map</a></li><li class="chapter-item "><a href="../../posts/js/js_tutorial_math.html"><strong aria-hidden="true">11.3.</strong> js math</a></li><li class="chapter-item "><a href="../../posts/js/js_tutorial_object.html"><strong aria-hidden="true">11.4.</strong> js object</a></li><li class="chapter-item "><a href="../../posts/js/js_tutorial_set.html"><strong aria-hidden="true">11.5.</strong> js set</a></li><li class="chapter-item "><a href="../../posts/js/single_thread_and_asynchronous.html"><strong aria-hidden="true">11.6.</strong> single thread and asynchronous</a></li><li class="chapter-item "><a href="../../posts/js/this.html"><strong aria-hidden="true">11.7.</strong> js this</a></li><li class="chapter-item "><a href="../../posts/js/js_implment_aes.html"><strong aria-hidden="true">11.8.</strong> js implment aes</a></li><li class="chapter-item "><a href="../../posts/js/getting_started_with_ajax.html"><strong aria-hidden="true">11.9.</strong> getting started with ajax</a></li><li class="chapter-item "><a href="../../posts/js/BinarySearchTree.html"><strong aria-hidden="true">11.10.</strong> binary search tree</a></li><li class="chapter-item "><a href="../../posts/js/goole_zx.html"><strong aria-hidden="true">11.11.</strong> goole zx</a></li><li class="chapter-item "><a href="../../posts/js/es6.html"><strong aria-hidden="true">11.12.</strong> es6</a></li></ol></li><li class="chapter-item "><a href="../../posts/ruby/ruby.html"><strong aria-hidden="true">12.</strong> Ruby</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/ruby/rails_setup_env.html"><strong aria-hidden="true">12.1.</strong> ruby on rails setup environment</a></li><li class="chapter-item "><a href="../../posts/ruby/learn_ruby.html"><strong aria-hidden="true">12.2.</strong> learn ruby</a></li><li class="chapter-item "><a href="../../posts/ruby/ruby_note.html"><strong aria-hidden="true">12.3.</strong> Ruby Note</a></li><li class="chapter-item "><a href="../../posts/ruby/setup_ruby_for_ctf.html"><strong aria-hidden="true">12.4.</strong> Setup ruby for CTF</a></li></ol></li><li class="chapter-item "><a href="../../posts/react/react.html"><strong aria-hidden="true">13.</strong> React</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/react/react_life_cycle.html"><strong aria-hidden="true">13.1.</strong> react life cycle</a></li><li class="chapter-item "><a href="../../posts/react/react_router.html"><strong aria-hidden="true">13.2.</strong> react router</a></li><li class="chapter-item "><a href="../../posts/react/react_this.html"><strong aria-hidden="true">13.3.</strong> react this</a></li><li class="chapter-item "><a href="../../posts/react/react_interviw.html"><strong aria-hidden="true">13.4.</strong> react interview</a></li><li class="chapter-item "><a href="../../posts/react/important_react_interview.html"><strong aria-hidden="true">13.5.</strong> important react interview</a></li><li class="chapter-item "><a href="../../posts/react/react_quick_reference.html"><strong aria-hidden="true">13.6.</strong> react quick reference</a></li><li class="chapter-item "><a href="../../posts/react/redux_quick_reference.html"><strong aria-hidden="true">13.7.</strong> redux quick reference</a></li></ol></li><li class="chapter-item "><a href="../../posts/vue/vue.html"><strong aria-hidden="true">14.</strong> Vue</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/vue/vue_ajax.html"><strong aria-hidden="true">14.1.</strong> vue ajax</a></li></ol></li><li class="chapter-item "><a href="../../posts/angular/angular.html"><strong aria-hidden="true">15.</strong> Angular</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/angular/controller_communication.html"><strong aria-hidden="true">15.1.</strong> controller communication</a></li><li class="chapter-item "><a href="../../posts/angular/creating_custom_directives.html"><strong aria-hidden="true">15.2.</strong> creating custom directives</a></li><li class="chapter-item "><a href="../../posts/angular/directive_notes.html"><strong aria-hidden="true">15.3.</strong> directive notes</a></li><li class="chapter-item "><a href="../../posts/angular/directive_communication.html"><strong aria-hidden="true">15.4.</strong> directive communication</a></li><li class="chapter-item "><a href="../../posts/angular/post_params.html"><strong aria-hidden="true">15.5.</strong> post params</a></li><li class="chapter-item "><a href="../../posts/angular/read_json_angular.html"><strong aria-hidden="true">15.6.</strong> read json angular</a></li><li class="chapter-item "><a href="../../posts/angular/same_route_reload.html"><strong aria-hidden="true">15.7.</strong> same route reload</a></li></ol></li><li class="chapter-item "><a href="../../posts/css/css.html"><strong aria-hidden="true">16.</strong> Css</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/css/use_css_media.html"><strong aria-hidden="true">16.1.</strong> use css media</a></li></ol></li><li class="chapter-item "><a href="../../posts/php/php.html"><strong aria-hidden="true">17.</strong> Php</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/php/for_php_string_implment_some_extemtion_functions.html"><strong aria-hidden="true">17.1.</strong> for php string implment some extemtion functions</a></li><li class="chapter-item "><a href="../../posts/php/php_cheatsheet.html"><strong aria-hidden="true">17.2.</strong> PHP cheatsheet</a></li></ol></li><li class="chapter-item "><a href="../../posts/leetcode/leetcode.html"><strong aria-hidden="true">18.</strong> Leetcode</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/leetcode/rust_leetcode.html"><strong aria-hidden="true">18.1.</strong> rust leetcode</a></li><li class="chapter-item "><a href="../../posts/leetcode/rust_codewar.html"><strong aria-hidden="true">18.2.</strong> rust codewar</a></li><li class="chapter-item "><a href="../../posts/leetcode/swift_codewar.html"><strong aria-hidden="true">18.3.</strong> swift codewar</a></li><li class="chapter-item "><a href="../../posts/leetcode/js_leetcode.html"><strong aria-hidden="true">18.4.</strong> js leetcode</a></li><li class="chapter-item "><a href="../../posts/leetcode/java_leetcode.html"><strong aria-hidden="true">18.5.</strong> java leetcode</a></li><li class="chapter-item "><a href="../../posts/leetcode/rust_huawei.html"><strong aria-hidden="true">18.6.</strong> huawei test</a></li><li class="chapter-item "><a href="../../posts/leetcode/rust_utils.html"><strong aria-hidden="true">18.7.</strong> rust common functions</a></li><li class="chapter-item "><a href="../../posts/leetcode/olympiad_training.html"><strong aria-hidden="true">18.8.</strong> Computer olympiad training</a></li></ol></li><li class="chapter-item "><a href="../../posts/ctf/CTF.html"><strong aria-hidden="true">19.</strong> CTF</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../posts/ctf/CTF_Note.html"><strong aria-hidden="true">19.1.</strong> CTF Note</a></li><li class="chapter-item "><a href="../../posts/ctf/0.1_Web.html"><strong aria-hidden="true">19.2.</strong> Web</a></li><li class="chapter-item "><a href="../../posts/ctf/4.1_Misc.html"><strong aria-hidden="true">19.3.</strong> Misc</a></li><li class="chapter-item "><a href="../../posts/ctf/3.2_PWN_note.html"><strong aria-hidden="true">19.4.</strong> PWN</a></li><li class="chapter-item "><a href="../../posts/ctf/3.1_Crypto.html"><strong aria-hidden="true">19.5.</strong> Crypto</a></li><li class="chapter-item "><a href="../../posts/ctf/3.4_RSA_note.html"><strong aria-hidden="true">19.6.</strong> Rsa attack</a></li><li class="chapter-item "><a href="../../posts/ctf/3.5_Base64.html"><strong aria-hidden="true">19.7.</strong> Base64</a></li><li class="chapter-item "><a href="../../posts/ctf/0.0_SQL Injection Cheatsheet.html"><strong aria-hidden="true">19.8.</strong> SQL Injection Cheatsheet</a></li><li class="chapter-item "><a href="../../posts/ctf/1.1_SQL_injection.html"><strong aria-hidden="true">19.9.</strong> SQL Injection</a></li><li class="chapter-item "><a href="../../posts/ctf/1.2_SQL_injection_UNION_attacks.html"><strong aria-hidden="true">19.10.</strong> SQL Injection UNION attacks</a></li><li class="chapter-item "><a href="../../posts/ctf/1.3_Blind SQL injection.html"><strong aria-hidden="true">19.11.</strong> Blind SQL Injection</a></li><li class="chapter-item "><a href="../../posts/ctf/1.4_Code Injection.html"><strong aria-hidden="true">19.12.</strong> Code Injection</a></li><li class="chapter-item "><a href="../../posts/ctf/1.5_SSRF.html"><strong aria-hidden="true">19.13.</strong> SSRF</a></li><li class="chapter-item "><a href="../../posts/ctf/1.6_OS command injection.html"><strong aria-hidden="true">19.14.</strong> OS command injection</a></li><li class="chapter-item "><a href="../../posts/ctf/1.7_Local file inclusion.html"><strong aria-hidden="true">19.15.</strong> Local file inclusion</a></li><li class="chapter-item "><a href="../../posts/ctf/1.8_Remote file inclusion.html"><strong aria-hidden="true">19.16.</strong> Remote file inclusion</a></li><li class="chapter-item "><a href="../../posts/ctf/1.9_CSRFm.html"><strong aria-hidden="true">19.17.</strong> CSRF</a></li><li class="chapter-item "><a href="../../posts/ctf/1.10_NoSQL injection.html"><strong aria-hidden="true">19.18.</strong> NoSQL injection</a></li><li class="chapter-item "><a href="../../posts/ctf/1.11_JSON injection.html"><strong aria-hidden="true">19.19.</strong> JSON injection</a></li><li class="chapter-item "><a href="../../posts/ctf/1.12_CTF_Web_SQL_Note.html"><strong aria-hidden="true">19.20.</strong> CTF Web SQL Note</a></li><li class="chapter-item "><a href="../../posts/ctf/2.1_XXE.html"><strong aria-hidden="true">19.21.</strong> XXE</a></li><li class="chapter-item "><a href="../../posts/ctf/2.2_XSS.html"><strong aria-hidden="true">19.22.</strong> XSS</a></li><li class="chapter-item "><a href="../../posts/ctf/2.3_Upload File.html"><strong aria-hidden="true">19.23.</strong> Upload File</a></li><li class="chapter-item "><a href="../../posts/ctf/2.4_serialize_unserialize.html"><strong aria-hidden="true">19.24.</strong> serialize unserialize</a></li><li class="chapter-item "><a href="../../posts/ctf/2.5_Race condition.html"><strong aria-hidden="true">19.25.</strong> Race condition</a></li><li class="chapter-item "><a href="../../posts/ctf/zip_plain_text_attack.html"><strong aria-hidden="true">19.26.</strong> Zip plain text attack</a></li><li class="chapter-item "><a href="../../posts/ctf/3.2_PWN_note.html"><strong aria-hidden="true">19.27.</strong> PWN_note</a></li><li class="chapter-item "><a href="../../posts/ctf/3.3_pwn HCTF2016 brop.html"><strong aria-hidden="true">19.28.</strong> pwn HCTF2016 brop</a></li><li class="chapter-item "><a href="../../posts/ctf/pwn_patch_defense_skill.html"><strong aria-hidden="true">19.29.</strong> PWN Patch defense skill</a></li><li class="chapter-item "><a href="../../posts/ctf/pwn_stack_overflow.html"><strong aria-hidden="true">19.30.</strong> PWN stack overflow</a></li><li class="chapter-item "><a href="../../posts/ctf/pwn_heap_overflow.html"><strong aria-hidden="true">19.31.</strong> PWN heap overflow</a></li><li class="chapter-item "><a href="../../posts/ctf/pwn_format_string_vulnerability.html"><strong aria-hidden="true">19.32.</strong> PWN Format String Vulnerability</a></li><li class="chapter-item "><a href="../../posts/ctf/kali_linux_tutorials.html"><strong aria-hidden="true">19.33.</strong> Kali linux tutorials</a></li><li class="chapter-item "><a href="../../posts/ctf/google_dorks_2023_lists.html"><strong aria-hidden="true">19.34.</strong> Google Dorks 2023 Lists</a></li><li class="chapter-item "><a href="../../posts/ctf/dvwa_writeup.html"><strong aria-hidden="true">19.35.</strong> DVWA WriteUp</a></li><li class="chapter-item "><a href="../../posts/ctf/bwapp_writeup.html"><strong aria-hidden="true">19.36.</strong> bWAPP WriteUp</a></li><li class="chapter-item "><a href="../../posts/ctf/sqlilabs_writeup.html"><strong aria-hidden="true">19.37.</strong> sqlilabs WriteUp</a></li><li class="chapter-item "><a href="../../posts/ctf/ctf_mindmap_list.html"><strong aria-hidden="true">19.38.</strong> ctf mindmap list</a></li></ol></li></ol>
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<h1 id="dart-cheat-sheet"><a class="header" href="#dart-cheat-sheet">dart-cheat-sheet</a></h1>
<p>A curated list of awesome stuff needed to get started with your flutter development journey</p>
<h2 id="table-of-contents"><a class="header" href="#table-of-contents">Table of Contents</a></h2>
<ul>
<li><a href="#string-interpolation">String interpolation</a></li>
<li><a href="#functions">Functions</a></li>
<li><a href="#parsing">Parsing</a></li>
<li><a href="#list-arrays">List Arrays</a></li>
<li><a href="#lambda-functions">Lambda Functions</a></li>
<li><a href="#null-aware-operators">Null-aware Operators</a></li>
<li><a href="#conditional-property-access">Conditional Property Access</a></li>
<li><a href="#collections-literals">Collections Literals</a></li>
<li><a href="#arrow-syntax">Arrow Syntax</a></li>
<li><a href="#iterations">Iterations</a></li>
<li><a href="#map">Map</a></li>
<li><a href="#variables">Variables</a></li>
<li><a href="#class">Class</a></li>
<li><a href="#getters-and-setters">Getters and Setters</a></li>
<li><a href="#future-async-await">Futures: Async and Await</a></li>
<li><a href="#json-and-serialization">JSON and serialization</a></li>
<li><a href="#Reading-and-decoding-a-file">Reading and decoding a file</a></li>
<li><a href="#sound-null-safety">Sound null safety</a></li>
</ul>
<h2 id="string-interpolation"><a class="header" href="#string-interpolation">String interpolation</a></h2>
<p>Every language has it’s own way of interpolating two or more words or characters. In dart, you can put value of an expression inside a string as follows:</p>
<h3 id="example"><a class="header" href="#example">Example</a></h3>
<pre><code class="language-dart">int x=6;
int y=2;
String sum = '${x+y}'; // result is 8
String subtraction = '${x-y}'; // result is 4
String upperCase = '${&quot;hello&quot;.toUpperCase()}'; // result is HELLO
String concatXY = '$x$y'; // result is '62'
</code></pre>
<h2 id="functions"><a class="header" href="#functions">Functions</a></h2>
<p>Dart lang is an OOL(Object-oriented language), In this language, functions are objects and have a type, Function. This implies that functions can be assigned to
variables or passed as args to other functions. Interestingly, you can also call an instance of a class as if it were a fuction. That’s awesome, right?</p>
<h3 id="example-1"><a class="header" href="#example-1">Example</a></h3>
<pre><code class="language-dart">String fullName(){
String firstName = &quot;Temidayo&quot;;
String lastName = &quot;Adefioye&quot;;
return '$firstName $lastName'; // returns 'Temidayo Adefioye'
}
</code></pre>
<pre><code class="language-dart">int length(String text){
return text.length; // returns length of text
}
</code></pre>
<p>The above function can be rewritten in a more concise way:</p>
<pre><code class="language-dart">int length(String text) =&gt; return text.length; // returns length of text
</code></pre>
<p>The above approach is applicable where functions contain just ONE expression. This is also referred to as shorthand syntax.</p>
<h2 id="parsing"><a class="header" href="#parsing">Parsing</a></h2>
<p>Parsing a string to a number such as integer and double is very key. As a developer, often times I need to convert(parse) a string value
coming from a server-side to a number, tryParse method comes in handy. Take a look at this code snippet:</p>
<h3 id="example-2"><a class="header" href="#example-2">Example</a></h3>
<pre><code class="language-dart">var a = &quot;121&quot;;
var b = &quot;120.56&quot;;
var c = &quot;100.a12&quot;;
var d = &quot;abc&quot;;
String parseA = int.tryParse(a); // result is 121
String parseB = double.tryParse(b); // result is 120.56
String parseC = double.tryParse(c); // result is null (that string contains invalid number)
String parseD = double.tryParse(d); // result is null (that string contains invalid number)
</code></pre>
<h2 id="list-arrays"><a class="header" href="#list-arrays">List Arrays</a></h2>
<p>Perhaps the most common collection in nearly every programming language is the array or ordered set of objects. Please note that Dart arrays are Lists.</p>
<h3 id="example-3"><a class="header" href="#example-3">Example</a></h3>
<pre><code class="language-dart">var numList = [1,2,3,5,6,7];
var countryList = [&quot;Nigeria&quot;,&quot;United States&quot;,&quot;United Kingdom&quot;,&quot;Ghana&quot;,&quot;IreLand&quot;,&quot;Germany&quot;];
String numLength = numList.length; // result is 6
String countryLength = countryList.length; // result is 6
String countryIndex = countryList[1]; // result is 'United States'
String numIndex = numList[0]; // result is 1
countryList.add(&quot;Poland&quot;); // Adds a new item to the list.
var emailList = new List(3); // Set a fixed list size
var emailList = new List&lt;String&gt;(); // instance of a list of type String
</code></pre>
<h2 id="lambda-functions"><a class="header" href="#lambda-functions">Lambda Functions</a></h2>
<p>Lambda functions provide you with a short and concise way of representing small functions. They are also referred to as Arrow functions. In dart, if you need to write quick throw away functions without necessarily naming them, lambda fucntion is all you need. With the power of this function you can do the following and more:</p>
<h3 id="example-4"><a class="header" href="#example-4">Example</a></h3>
<pre><code class="language-dart">var numList = new List&lt;int&gt;.generate(5,(i) =&gt; i);
print(numList); //result: {0,1,2,3,4}
var loans = numList.map( (n) =&gt; &quot;\#$n&quot;).toList();
print(loans); // result: {#0, #1, #3, #4}
printMsg()=&gt; print(&quot;Hello world&quot;);
// You can declare a state function this way in flutter
_DashboardState createState() =&gt; _DashboardState();
// How about creating a widget using lambda?
Card makeCard(Asset assetViewModel) =&gt; Card(
elevation: 8.0,
margin: new EdgeInsets.symmetric(horizontal: 10.0, vertical: 6.0),
child: Container(
decoration: BoxDecoration(color: Colors.white),
child: makeListTile(assetViewModel), // where makeListTile is a custom widget created already
),
);
</code></pre>
<h2 id="null-aware-operators"><a class="header" href="#null-aware-operators">Null-aware Operators</a></h2>
<p>Handling null exceptions in app development is very essential, as this allows you to create a seamless experience for your app users. Dart provides you with some handy operators for dealing with values that might be null. One is the ??= assignment operator, which assigns a value of a variable only if that variable is currently null:</p>
<h3 id="example-5"><a class="header" href="#example-5">Example</a></h3>
<pre><code class="language-dart">int x; // The initial value of any object is null
x ??=6;
print(x); // result: 6
x ??=3;
print(x); // result is still 6
print(null ?? 10); // result: 10. Display the value on the left if it's not null else return the value on the right
</code></pre>
<h2 id="conditional-property-access"><a class="header" href="#conditional-property-access">Conditional Property Access</a></h2>
<p>To properly safegaurd access to a property or method of an object that might be null, put a question mark (?) before the (.)</p>
<h3 id="example-6"><a class="header" href="#example-6">Example</a></h3>
<pre><code class="language-dart">userObject?.userName
//The code snippet above is equivalent to following:
(userObject !=null) ? userObject.userName : null
//You can chain multiple uses of ?. together in a single expression
userObject?.userName?.toString()
// The preceeding code returns null and never calls toString() if either userObject or userObject.userName is null
</code></pre>
<h2 id="collections-literals"><a class="header" href="#collections-literals">Collections Literals</a></h2>
<p>With literals you can create Dart’s built-in lists, maps and sets without hassle.</p>
<h3 id="example-7"><a class="header" href="#example-7">Example</a></h3>
<pre><code class="language-dart">final fruitList = [&quot;Orange&quot;,&quot;Bannana&quot;,&quot;Carrot&quot;,&quot;Apple&quot;]; // A list of fruit
final countrySet = {&quot;Nigeria&quot;,&quot;United States&quot;,&quot;Poland&quot;,&quot;Italy&quot;}; // A set of country
final credMap = {
'userName': 'temi',
'password': 'xmen'
} // A map of user credentials
</code></pre>
<p>You maybe wondering why we didn’t explicitly declare a type for all of the collections above. It’s interesting to know that dart’s type inference can assign types to these variables for you. In this case, the inferred types are List<String>, Set<String> and Map&lt;String,String&gt;.
Please note that you can choose to specify a type for your variable declaration like this:</p>
<pre><code class="language-dart">final fruitList = &lt;String&gt;[];
final countrySet = &lt;String&gt;{};
final credMap = &lt;String, String&gt;{};
</code></pre>
<h2 id="arrow-syntax"><a class="header" href="#arrow-syntax">Arrow Syntax</a></h2>
<p>Remember Lambda Functions as discussed earlier in this sheet? We used a symbol =&gt; to define our lambda expression. You can check out Lambda function section for more explanation.</p>
<h3 id="example-8"><a class="header" href="#example-8">Example</a></h3>
<pre><code class="language-dart">String _firstName = &quot;Michael&quot;;
String _lastName = &quot;Jones&quot;;
String _middleName = &quot;Will&quot;;
String get fullName =&gt; '$_firstName $_middleName $_lastName'; // result: 'Michael Will Jones'
</code></pre>
<h2 id="iterations"><a class="header" href="#iterations">Iterations</a></h2>
<p>Just like every other programming language out there, you can perform iterations in dart. Here is a for loop example</p>
<h3 id="example-9"><a class="header" href="#example-9">Example</a></h3>
<pre><code class="language-dart">for (int i=0; i&lt;=20; i++){
print(i); // prints 1 to 20
}
var fruitList = [&quot;Orange&quot;,&quot;Bannana&quot;,&quot;Carrot&quot;,&quot;Apple&quot;];
for (final fruit in fruits){
print(fruit); // prints all types of fruit in the list
}
</code></pre>
<h2 id="map"><a class="header" href="#map">Map</a></h2>
<p>Map can either be declared using literals or map constructor. To learn more about map declaration using literals, please go to the Collections Literals section. Here is how you can declare map using a map constructor:</p>
<h3 id="example-10"><a class="header" href="#example-10">Example</a></h3>
<pre><code class="language-dart">var user = new Map();
// To initialize the map, do this:
user['firstName'] = 'Paul';
user['lastName'] = 'Pogba';
// Result: {firstName: Paul, lastName: Pogba}
// Below are map properties
- Keys
- Values
- Length
- isEmpty
- isNotEmpty
// Below are map functions
- addAll()
- clear()
- remove()
- forEach()
</code></pre>
<h2 id="variables"><a class="header" href="#variables">Variables</a></h2>
<p>Here’s an example of creating a variable and initializing it:</p>
<h3 id="example-11"><a class="header" href="#example-11">Example</a></h3>
<pre><code class="language-dart">int x = 2; // explicitly typed
var p = 5; // type inferred
p = &quot;cool&quot;; // ops! throws an error
dynamic z = 8; // variable can take on any type
z = &quot;cool&quot;; // cool
// if you never intend to change a variable use final or const. Something like this:
final email = &quot;temid@gmail.com&quot;; // you can't change the value
final String email = &quot;temid@gmail.com&quot;; // you can't change the value
// iPhone 11 Pro max calculator using const
const qty = 5;
const totalCost = 1099 * qty;
</code></pre>
<h2 id="class"><a class="header" href="#class">Class</a></h2>
<p>In Dart, the class keyword is used to declare a class. Here is a basic example:</p>
<h3 id="example-12"><a class="header" href="#example-12">Example</a></h3>
<pre><code class="language-dart">class Car {
// field
String engine = &quot;E1001&quot;;
// function
void disp() {
print(engine);
}
}
</code></pre>
<h2 id="getters-and-setters"><a class="header" href="#getters-and-setters">Getters and Setters</a></h2>
<p>Getters and setters are special methods that provide read and write access to an object’s properties. Each instance variable of your class has an implicit getter, and a setter if needed. In dart, you can take this even further by implementing your own getters and setters. If you’ve had any experience in Object-Oriented Programming you’ll feel right at home. Here is a basic syntax for a class:</p>
<h3 id="example-13"><a class="header" href="#example-13">Example</a></h3>
<pre><code class="language-dart">class className {
fields;
getters/setters
constructor
methods/functions
}
</code></pre>
<pre><code class="language-dart">class Person {
String firstName;
String lastName;
double height;
int personAge;
int yearofBirth;
double weight;
int get age {
return personAge;
}
void set age(int currentYear) {
personAge = currentYear - yearofBirth;
}
// We can also eliminate the setter and just use a getter.
//int get age {
// return DateTime.now().year - yearofBirth;
//}
Person({this.firstName,this.lastName,this.personAge,this.yearofBirth,this.weight});
}
</code></pre>
<p>We can implement Person class this way:</p>
<pre><code class="language-dart">void main() {
Person person = Person(firstName:&quot;Thanos&quot;,lastName:&quot;Rednos&quot;,yearofBirth:1990,weight:200.5);
print(person.firstName); // output - Thanos
print(person.lastName); // output - Rednos
person.age = 2019;
print(person.age); // output - 29
}
</code></pre>
<h2 id="futures-async-and-await"><a class="header" href="#futures-async-and-await">Futures: Async and Await</a></h2>
<p>The async and await keywords provide a declarative way to define asynchronous functions and use their results. Remember these two basic guidelines when using async and await:</p>
<ul>
<li>To define an async function, add async before the function body:</li>
<li>The await keyword works only in async functions.</li>
</ul>
<h3 id="example-14"><a class="header" href="#example-14">Example</a></h3>
<pre><code class="language-dart">Future&lt;String&gt; login() {
// Imagine that this function is
// more complex and slow.
String userName=&quot;Temidjoy&quot;;
return
Future.delayed(
Duration(seconds: 4), () =&gt; userName);
}
// Asynchronous
main() async {
print('Authenticating please wait...');
print(await userName());
}
</code></pre>
<h2 id="json-and-serialization"><a class="header" href="#json-and-serialization">JSON and serialization</a></h2>
<p>Most mobile and web apps use JSON for tasks such as exchanging data with a web server. With Dart support for JSON serialization and deserialization: converting Dart objects to and from JSON, data exchange is made easy in flutter development.
The following libraries and packages are useful across Dart platform:</p>
<ul>
<li><a href="https://dart.dev/guides/libraries/library-tour#dartconvert---decoding-and-encoding-json-utf-8-and-more">dart:convert</a>
Converters for both JSON and UTF-8 (the character encoding that JSON requires).</li>
<li><a href="https://pub.dev/packages/json_serializable">package:json_serializable</a>
An easy-to-use code generation package. When you add some metadata annotations and use the builder provided by this package, the Dart build system generates serialization and deserialization code for you.</li>
<li><a href="https://pub.dev/packages/built_value">package:built_value</a>
A powerful, opinionated alternative to json_serializable.
You need to serialize and deserialize JSON in your Flutter project? <a href="https://flutter.dev/docs/development/data-and-backend/json">see this example</a> to quickly get started.</li>
</ul>
<h2 id="reading-and-decoding-a-file"><a class="header" href="#reading-and-decoding-a-file">Reading and decoding a file</a></h2>
<p>The code snippet below reads a file and runs two transforms over the stream. It first converts the data from UTF8 and then runs it through a LineSplitter. All lines are printed, except any that begin with a hashtag, #.</p>
<h3 id="example-15"><a class="header" href="#example-15">Example</a></h3>
<pre><code class="language-dart">import 'dart:convert';
import 'dart:io';
Future&lt;void&gt; main(List&lt;String&gt; args) async {
var file = File(args[0]);
var lines = utf8.decoder
.bind(file.openRead())
.transform(LineSplitter());
await for (var line in lines) {
if (!line.startsWith('#')) print(line);
}
}
</code></pre>
<h2 id="sound-null-safety"><a class="header" href="#sound-null-safety">Sound null safety</a></h2>
<p>Sound null safety is now supported by the Dart language!
When you choose to use null safety, types in your code are by default non-nullable, which means variables cannot contain null unless you explicitly allow it. Your runtime null-dereference mistakes become edit-time analysis errors with null safety.
The variables in the following code are all non-nullable thanks to null safety:</p>
<pre><code class="language-dart">// None of these can ever be null in null-safe Dart.
var x = 81; // Inferred to be an int.
String address = getAddress();
final c = Car();
</code></pre>
<p>Simply add ? to a variable’s type declaration to indicate that it might be null:</p>
<pre><code class="language-dart">// This is now a nullable Int.
int? x = null;
</code></pre>
<h3 id="enabling-null-safety"><a class="header" href="#enabling-null-safety">Enabling null safety</a></h3>
<p>Sound null safety is available in Dart 2.12 and Flutter 2.</p>
<h3 id="migrating-an-existing-package-or-app"><a class="header" href="#migrating-an-existing-package-or-app">Migrating an existing package or app</a></h3>
<p>For instructions on how to migrate your code to null safety, see the <a href="https://dart.dev/null-safety/migration-guide">migration guide</a>.</p>
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