【Web前端】JavaScript中（for...in/of）区别浅析

for(...in...)循环输出数组下标

for(...of...)循环输出数组的值

var arr = ["a","b","c","d"];

//in：循环输出数组下标
for(let i in arr){
	console.log(i);		//0,1,2,3
}
//of：循环输出数组的值
for(let i of arr){
	console.log(i);		//a,b,c,d
}