JS数组及对象遍历方法代码汇总

var arrTmp = ["value1","value2","value3"];
var objTmp = {
  aa:"value1",
  bb:"value2",
  cc:function(){
    console.log("value3")
  }
}

/****js原生遍历****/
//for循环遍历数组
for(var i=0;i

//for-in遍历数组
for(var i in arrTmp){
  console.log(i+": "+arrTmp[i])
}
//for-in会遍历到数组的属性
arrTmp.name="myTest";
for(var i in arrTmp){
  console.log(i+":"+arrTmp[i])
}
//输出 0:value1 1:value2 2:value3 name:myTest

//只会输出value1 value2
for(var i=0;i

// for-of遍历数组，不带索引，i即为数组元素
for(let i of arrTmp){
  console.log(i)
}
//输出 "value1" "value2" "value3"
 
// for-of遍历Map对象
let iterable = new Map([["a", 1], ["b", 2], ["c", 3]]);
for (let [key, value] of iterable) {
 console.log(value);
}
//输出 1 2 3
 
// for-of遍历字符串
let iterable = "china中国";
for (let value of iterable) {
 console.log(value);
}
//输出 "c" "h" "i" "n" "a" "中" "国"

/****Object.keys()返回键名数组****/
//数组类型
let arr = ["a", "b", "c"];
console.log(Object.keys(arr));
// (3) ['0', '1', '2']
 
// 类数组对象
let anObj = { 100: 'a', 2: 'b', 7: 'c' };
console.log(Object.keys(anObj));
// (3) ['2', '7', '100']
 
//一般对象
let xyz = {z: "zzz", x: "xxx", y: "yyy"};
console.log(Object.keys(xyz));
// (3) ["z", "x", "y"]

/****$.each()遍历对象和数组****/
$.each(arrTmp,function(index,value){
  console.log(index+": "+value)
});
 
$.each(objTmp,function(key,value){
  console.log(key+": "+value)
});