javascript - 怎么用JS实现concat()方法

Question

想手动实现concat()方法，实现过程中除了concat()其他方法可以随意调用，但实现不出来，求助~~

Answer 1

Array.prototype.concat1=function(){
    var arr=this.slice(0)
    arguments.forEach(function(x){
        if(x instanceof Array){
            x.forEach(function(y){
                arr.push(y)
            })
        }else{
            arr.push(x)
        }
    })
    return arr
}

Answer 2

Array.prototype.test = function() {
    var arr = JSON.parse(JSON.stringify(this)); // 用JSON可以深度拷贝数组
    for (var i = 0; i < arguments.length; i++) {
        var argo = arguments[i]; 
        for ( var j = 0; j < argo.length; j++ ) {
            arr.push(argo[j]);
        }
    };
    return arr;
}

var arr1 = [1,2,3], arr2 = ['a','b','c'];

console.log(arr1.test(arr2));
console.log(arr1);
console.log(arr2);

Answer 3

要这样？

    <script type="text/javascript">
    function concat() {
        var arr = [];
        for (var i = 0; i < arguments.length; i++) {
            arr.push(arguments[i]);
        };
        return arr.toString().replace(/,/g, '');
    }
    var foo = concat('hi ', 'jack', 111); //随便输入任意数量字符串参数
    console.log(foo);
    </script>

Answer 4

var a = [1, 2, 3];
var b = [3, 4, 5];
var c = {a:1};
function concats(){
  var arr = [];
  for (var i=0, lens=arguments.length; i<lens; i++){
    for (var j=0, len=arguments[i].length; j<len; j++){
      arr.push(arguments[i][j]);
    }
  }
  return arr;
}
console.log(concats(a, c, b));

Answer 5

如果参数里没有二维数组可以试试这样

function concat() {
    var args = Array.prototype.slice.call(arguments,0),
        array = [];
    args.forEach(function(item){
        array.push(item);
    })
    return array.join(",").split(",");
}