2种写法问题在哪里？

Question

var arr1=new Array("a","b","c");        var arr2=new Array("d","e","f");var arr3=arr1.concat(arr2);和var arr1=new Array("a","b","c");        var arr2=new Array("d","e","f");var arr3=new Array();myarr3=arr3.concat(arr1,arr2);一般都是按第二种方法写， 第一种写法有什么问题吗？求详细解答

Answer 1

没有问题