Vue JS 学习笔记

...    扩展运算符
var [list1,...list2]=[]
console.log(list1);
console.log(list2);
list1 为undefined
list2 为空数组

var map=new Map();
map.set("map1","ace");
map.set("map2","ace2");
var newmap=[...map];
console.log(newmap)
0: (2) ['map1', 'ace']
1: (2) ['map2', 'ace2']


... 扩展运算符可作用于：string(转为char 数组) array（转为一个新数组）map 

Some
var ultramans = ["Zoffy","Man","Seven","Jack","Ace","Taro"];
//some类似C#中的Any()
 var hasValue = ultramans.some(m=>m=="Jack");
出现的是bool 值


//filter可以筛选数组的内容，类似C#中的FindAll()方法
 var us = ultramans.filter(m=>m=="Jack");
返回的是一个符合条件的新数组

模拟实现filter
var ultramans = ["Zoffy","Man","Seven","Jack","Ace","Taro"];
var us = myFilter(ultramans,(item)=>item=='Ace')

function myFilter(array,fun){
    var newArray=[];
    for (let i = 0; i < array.length; i++) {
        var item = array[i]
        var bool = fun(item);
        if(bool) newArray.push(item);
    }
   return newArray;
}
console.log('us :>> ', us);

//类比于C#中的All方法，当然所有元素都符合某个条件时，返回真
var allRight = ultramans.every(m=>m=="Ace");
// 类比于C# 中的Contact
var hasEl = ultramans.includes("Ace");


//concat 连接数组
var list1=[1,2,3,4,5];
var list2=[6,7,8,9,10];
var list = list1.concat(list2);
console.log(list);
结果 [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]