var arr = [1,3,6,912,16,18];
for(var i = 0;i<arr.length;i++){
console.log(arr[i])
}
var arr = [1,3,6,912,16,18]; arr.forEach((item,index)=>{ console.log(item,index) //item代表每一项的值；index代表索引 })
var arr = [1,3,6,912,16,18]; arr.map((item,index){ console.log(item,index) //也可以return return item+5 })
var arr = [1,3,6,912,16,18]; for(let k in arr){ console.log(arr[k]) }
var arr = [1,3,6,912,16,18]; for(let key of arr){ console.log(arr[key]) }
item值
index索引
原文：https://www.cnblogs.com/guqzhoublog/p/13215051.html