不甜呐的博客

js遍历数组 1.普通for循环 var arr = [1,4,45,34,12,45,56,8]; for ( var i = 0; i <arr.length; i++){ console.log(arr[i]); }; 2.优化的for循环：将数组的长度存储起来，避免重复获取长度，数组越大时优化效果越明显 var arr = [1,4,45,34,12,45,56,8]; var len = arr.length; for ( var i = 0; i <len; i+