for循环和for in 循环 for of循环的区别
//for循环和for in 循环 for of循环的区别 let array = [1, 2, 3, 4, 5]; array.qqq = 123; for(let i = 0; i < array.length; i++){ console.log(array[i]);//1, 2, 3, 4, 5 } for(let k in array){//一般需要判断hasOwnProperty console.log(array[k]);//1, 2, 3, 4, 5, 123 } for(let value of array){ console.log(value);//value是数组中的值 1,2,3,4,5 }