var arr=[{a:1},{a:3},{a:2}];

function objSort(prop){

				 return function (obj1, obj2) {

        var val1 = obj1[prop];

        var val2 = obj2[prop];

        if (!isNaN(Number(val1)) && !isNaN(Number(val2))) {

            val1 = Number(val1);

            val2 = Number(val2);

        }

        if (val1 < val2) {

            return -1;

        } else if (val1 > val2) {

            return 1;

        } else {

            return 0;

        }

    }

}

arr.sort(objSort('a'));    //var arr=[{a:1},{a:2},{a:3}];

(上面代码返回的升序，如果想返回降序把“return -1“ 和 “return 1” 跳转一下位置)