Flutter learning (a) of Dart basis

table of Contents

• Dart development environment installation
• Dart basic concepts
• Dart built-in type
• Dart method
• Dart operator

Dart development environment installation

Dart Installation Overview

Mac installation DartSdk

Update dart

brew update dart

Dar check whether the installation was successful

dart --version

Set dart environment variable environment

vim .bash_profile

export PATH = ${PATH}:dartSdk的bin路劲

VSCode Dart environment installation

DartPad

DartPad online environment

Dart basic concepts

Dart sample program

Keyword

variable

Dart built-in type

int type

double type

String

Boolean

List

//支持...和...?
var list = [1,2,3];
var list = null;
var newList = [0,...list]; 
var newList = [0,...?list2];  //如果list2不为空，则插入元素到新数组
//collection if 和 collection for
var newList = [0,if(1<2) 3]; //根据条件 ，将结果插入到新数组
var newList = [0,for(int i: list) $i ] //将list中的元素依次插入到新数组

Set (2.3 incorporation)

//两种初始化空set的方式
Set<int> set = <int>{};
set = dynamic{}

Map

var a = {a:'1',b:'2'}
//空Map
var a = {}

Runes

Symbols

Dart method

parameter

Optional parameters

Named parameters

positional parameters

The method is first-class objects

   void log (e){
        println(e)
   }
   
   //方法可以当做参数
   list.forEach(log);
   
   //方法可以赋值
   var print = (e) => "xxxx ${e}";
   

main method

Scope

The method of determining whether the same

Method returns a value

Dart operator

Priority operator is from top to bottom, left to right (in the order of the figure above)

Dart concatenation operator