public class Copy1 { public static void main(String[] args) { array1(); //如果不初始化元素,默认为0 int [][] a = new int [][]{{1,3,2,5,7},{5,9,3,4,2}}; int [][] b = new int [a[1].length][a.length]; for(int i=0;i<b.length;i++){ //数组的转置 for(int j =0;j<b[i].length…
forEach()取出数组中2的倍数和3的倍数的数 //for IE if(!Array.prototype.forEach){ Array.prototype.forEach = function(callback, thisArg){ var T, k; if(this == null){ throw new TypeError(" this is null or not defined"); } var O = Object(this); var len = O.length &…
var a = [1,2,3]; var sum = 0; //传一个参数 a.forEach(function(v){ sum += v; }); console.log(sum);//6 //传三个参数(元素值,索引,数组本身) a.forEach(function(v,i,a){ a[i]=v+1;//为数组的各元素自加1 }) console.log(a);//[2,3,4]…