Dart List Set Map常用属性和方法

import 'package:flutter/material.dart';



void main() {
  //map俩种定义方法
  Map person={
    "name":"张三",
    "age":20,
    "sex":"男"
  };

  var person02 = new Map();
  person02["name"]="张三";
  print(person);
  print(person02);

  print(person.keys.toList());
  print(person.values.toList());
  print(person.isEmpty);//是否为空
  print(person.isNotEmpty);//是否不为空
  person.addAll({//增加属性
    "work":['敲代码','送外卖'],
    'height':150
  });
  print(person);
  person.remove("sex");//删除属性
  print(person);

  print(person.containsKey("name"));//查看键是否存在,存在返回true否则false
  print(person.containsValue("张三"));//查看值是否存在,存在返回true否则false

  //循环数据List Set Map通用
  List list=["one","two","three","four"];
  for(var item in list){
    print(item);
  }
  print("--------------");

  list.forEach((value){
    print("$value");
  });

  //返回的list里面的值每个乘以2
  List list02=[1,2,3];
  list02=list02.map((value){
   return value*2;
  }).toList();

  print(list02);

  list02=list02.where((value){//返回满足条件的值
    return value>3;
  }).toList();
  print(list02);

  var any = list02.any((value){//只要集合里有满足条件的值就返回true,否则false;
    return value>5;
  });

  print(any);

  var any02=list02.every((value){//集合里所有值满足条件返回true,否则false;
    return value>5;
  });

  print(any02);
  
  print("---------");
  //map循环
  person.forEach((key,value){
    print("$key:$value");
  });