[dart] a programming language for cross end development

Catalog

One 、Dart Language Overview ：

Dart Language features ：

Dart library ：

Dart platform ：

Web Platform Dart ( Use JavaScript Development and deployment )：

Dart Runtime environment ：

Two 、 To configure Dart development environment ：

obtain Dart SDK stay Windows In the environment ：

obtain Dart SDK stay Linux In the environment ：

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        OK, As a technical engineer , I want to know everything , So this is Google's programming language for cross end development Dart A record of learning ！

        free And Open source ？？？

        Let‘s do it ！

One 、Dart Language Overview ：

        Dart It is a language optimized for customers , Fast applications can be developed on any platform . Its goal is to provide the most efficient programming language for multi platform development , It also matches the application framework with a flexible runtime execution platform .

         Generally speaking , The programming language will contain some   technology barrier , That is, the choice of language in design determines its function and advantages . Dart The language is designed for client development , It gives priority to multi platform (Web, Mobile and desktop ) On the development of ( Sub second state thermal overload ) And high-quality production environment experience .

        Dart It's also  Flutter  The basis of . Dart As Flutter The programming language of the application , It provides an environment for driving application running , meanwhile Dart It also supports many core development tasks , For example, format , Analysis and code testing .

        The overview comes from official documents , Maybe this is a very nice A programming language for , It can carry out cross end development （PS： What is cross end development ？ Is to write a set of code , The implementation can run on different platforms ！ It's kind of similar Java Of JVM, In fact, it is a similar implementation , Because it provides Runtime execution platform ）

Dart Language features ：

        Dart Languages are type safe ; It uses static type checking to ensure the value of variables   Throughout   Match the static type of the variable . This is also called sound type . Although the type is mandatory , But because of Dart Support type inference , Type annotations are still optional . Dart The type system of is also very flexible , Allow the combination of dynamic Type and runtime checks , During test development , Or when encountering code that needs to be specially specified as dynamic type , This feature is very helpful .

         Unlike many other empty security languages , Dart Provide   Sound null safety , This means that only if you declare that the value can be empty , Value can be empty ; When Dart When determining that the variable cannot be empty , The variable   forever   Do not empty . With sound null safety ,Dart Static code analysis can protect you from null exceptions at run time . If you review running code in the debugger , You will see that non nullability is still preserved at runtime ( So it is completely null safe ).

        OK, Here we mentioned a bearish value safety , Be similar to Rust Variable variability , It's probably that a so-called variable declared is actually immutable unless it shows that it is declared to be a variable .Dart It can be null only when a reference is declared null , Otherwise, he can never be empty ！

Dart library ：

        Dart Have   Rich core library , It provides necessary tools for many daily programming tasks ：

• For each Dart Built in types provided by the program , Collections and other core functions (dart:core)

• Richer collection types , Such as queues 、 Link list 、 Hash graph and binary tree (dart:collection)

• It is used to convert encoder and decoder between different data representations , Include JSON and UTF-8 (dart:convert)

• Mathematical constants and functions , And random number generation (dart:math)

• For the wrong Web Files provided by the application 、 Socket 、HTTP And others I/O Support (dart:io)

• Asynchronous programming support , such as  Future  and  Stream  class (dart:async)

• It can effectively handle fixed size data （ for example , Unsigned 8 Byte integer ） and SIMD List of numeric types (dart:typed_data)

• For providing C External function interface supported by language style code interoperability (dart:ffi)

• Use  isolates  Concurrent programming — These independent working programs are similar to threads, but they do not share memory and communicate only through messages (dart:isolate)

• be based on Web The application needs to work with browser and document object models (DOM) The interaction of HTML Elements and other resources (dart:html)

         In addition to the core library ,Dart Many are also provided through a complete set of software packages API. Dart The team released many useful supplemental packages , for example ：

• characters ( character )

• intl ( internationalization )

• http (http request )

• crypto ( Hash encryption )

• markdown

         Besides , Third party publishers and the wider community have also released thousands of software packages , Support such functions ：

• XML

• Windows integration (Windows API call )

• SQLite

• compression ( Compress )

         You can visit   Library overview , View about Dart A series of examples of the core library . If you want to find something else API, Please see the   Common package pages .

Dart platform ：

Dart Compiler technology allows you to run code in different ways ：

• Native platform ： For mobile and desktop applications , Dart Have real-time (JIT) Compilation function Dart VM And advance for generating machine code (AOT) compiler .

• Web platform ： For Web Applications for , Dart Have a development time compiler (dartdevc) And production time compilers (dart2js). Both compilers can convert Dart Convert to JavaScript.

        Flutter frame   It is a popular multi platform UI tool kit , from Dart Language is strongly driven , Provide a set of tools and UI library , Help developers in iOS、Android、macOS、Windows、Linux and Web Platform construction is excellent UI Experience .

Native platform Dart (JIT and AOT Machine code )

         In the development process , A fast development cycle is critical for iterations . Dart VM Provides a real-time compiler (JIT), The compiler has incremental recompile function ( Support for hot overload )、 Run data collection （ For driving  DevTools） And rich development and debugging support .

         When an application can be deployed to a production environment ( Whether it's publishing to the app store or deploying to the production backend ), Dart AOT The compiler provides native ARM or x64 Machine coded AOT compile . after AOT The compiled application will start stably and quickly .

         after AOT The compiled code will be efficient Dart Run in the running environment , The operating environment has a sound Dart Type system , And use fast object allocation and   Generational garbage collector   To manage memory .

More information ：

• Quick start ： Command line and server application

• be used for JIT Run or AOT Compiled into machine code  dart  Tools

• Write command line applications

• To write HTTP The server

Web Platform Dart ( Use JavaScript Development and deployment )：

        Dart Of Web Support allows you to JavaScript Driven web platform Dart Code . Use Web In the environment Dart when , You can take Dart Compiled to run in the browser JavaScript Code , for example : Chrome  Medium  V8.

        Dart Web It includes an incremental development compiler that can realize a rapid development cycle , There are also compilers optimized for production environments dart2js. The latter uses techniques similar to removing inaccessible code , take Dart Code compiled as fast 、 compact 、 Deployable anytime, anywhere JavaScript.

More information ：

• Quick start ： Web applications

• dart2js compiler

• dartdevc compiler

• webdev  Tools

• Tips for web page deployment

Dart Runtime environment ：

         No matter which platform you use 、 Choose how to build your code , When executing code, you need a Dart Runtime environment . This runtime environment is responsible for the following key tasks ：

• memory management ： Dart Use a managed memory model , Unused memory is collected by the garbage collector (GC) Recycling .

• perform Dart The type system of language ： Dart Most type checking in languages is static （ Compile time ）, But there are still some checks that are dynamic （ Runtime ）. such as ,Dart The runtime environment will encounter   Type judgment operator   Perform dynamic check when .

• management  isolates： Dart The runtime environment is responsible for controlling the master isolate（ Code usually runs here ） And other applications isolate.

         On native platforms ,Dart The runtime environment is automatically included in a separate executable , yes  dart run  Command provided Dart VM Part of .

        OK, Indeed, there is not much to say behind , Just copy the official website directly , Links are as follows ：

Dart overview | DartDart A brief introduction https://dart.cn/overview

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Two 、 To configure Dart development environment ：

obtain Dart SDK stay Windows In the environment ：

        The installation method provided on the official website ：

obtain Dart SDK | Dart get Dart Command line tools and libraries , Used to write Dart web, Command line and server application .https://dart.cn/get-dart

         open Windows Of CMD Command line window ：

choco install dart-sdk

        Enter the above command , Start installation Dart SDK！

        SDK By default, it will be installed in  C:\tools\dart-sdk. You can change  ChocolateyToolsLocation  Environment variables to select the installation directory .

         If you cannot use it after installation Dart SDK The executable of , Please put SDK Add path to PATH：

1. open Windows Search for , Input  env.

2. Click on   Edit system environment variables .

3. Click on   environment variable (N)….

4. In the user variables section , choice  Path  And click the   edit (E)….

5. Click on   newly build (N), Input  dart-sdk  The path of .

6. Click... In each open window   application (A)  or   determine , Close the pop-up window and apply the path modification .

obtain Dart SDK stay Linux In the environment ： 

1. Update source information ：

sudo apt-get update

2. install apt-transport-https

sudo apt-get install apt-transport-https

3. Load profile ：

wget -qO- https://dl.google.com/linux/linux_signing_key.pub | sudo gpg --dearmor -o /usr/share/keyrings/dart.gpg

echo 'deb [signed-by=/usr/share/keyrings/dart.gpg arch=amd64] https://storage.flutter-io.cn/download.dartlang.org/linux/debian stable main' | sudo tee /etc/apt/sources.list.d/dart_stable.list

4. Start installation Dart：

sudo apt-get update
sudo apt-get install dart

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         The above is the official download method , I tried ......Linux It seems not so good ......      

        SO, I downloaded. ,ZIP Compressed package ：

  file | Dart Download a specific stable version 、 The beta 、 Development version and main branch development version Dart SDK and Dart API file .https://dart.cn/get-dart/archive       

         download ZIP After the package , Select a SDK File path , Configure it profile file , Then casually source Here's the configuration file

        The installation is probably completed Dart SDK Is that right ......

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        If you have any questions, please send a private letter or comment , Reply as soon as you see it ！ come on. , With all of you , Mutual encouragement ！！！