es5, es6 수조 반복 방법

ES5:

1、for

let items=[1,2,3,4,5]
for(let i=0;i<items.length;i++){
    console.log(items[i])	//1 2 3 4 5
}

2、forEach

items.forEach(function(item){    // break、continue
    console.log(item)   //1 2 3 4 5
})

3、every

items.every(function(item){    // return
    console.log(item)   //1 2 3 4 5
    return true
})

4、for in

for (const index in items) {
    console.log(index,items[index])
}

items.a=6
for (const index in items) {	//// ， 
    console.log(index,items[index])	
}

ES6

5、for of

let items=[1,2,3,4,5]
for (let item of items) {	// 
    console.log(item)   //1 2 3 4 5
}