js怎么对Array进行操作

js如何对Array进行操作！
var OldArray = {
a,
1,
5,
3,
b,
6,
2
};

现在要获得一个新的NewArray，要求两个：一是为数字；二是大于3.如何得到这个新的NewArray!

[解决办法]

JScript code

    function aa() {            var OldArray = [];            OldArray[0] = "a";            OldArray[1] = "1";            OldArray[2] = "5";            OldArray[3] = "3";            OldArray[4] = "b";            OldArray[5] = "6";            OldArray[6] = "2";            OldArray[7] = "a";            debugger;            var NewArray = [];            for (var i = 0; i < OldArray.length; i++) {                if (!isNaN(OldArray[i])) {                    if (Number(OldArray[i]) > 3) {                        NewArray[Number(NewArray.length)] = OldArray[i];                    }                }            }            var str = "";            for (var i = 0; i < NewArray.length; i++) {                str += ("-" + NewArray[i])            }            alert(str);        }
[解决办法]
JScript code
  var OldArray =['a', 1, 5, 3, 'b', 6, 2, 7];            var NewArray = [];            var pattern = /\d+/;            for (var i in OldArray) {                if (pattern.test(OldArray[i])) {                    if (OldArray[i] >3) {                        NewArray.push(OldArray[i]);                    }                }            }