JS求数组差集

自定义求两个数组的差集

var a = [1, 2, 3];var b = [2, 3, 4, 5];function cha(a, b) {    var res = [];    for(var i = 0, len = a.length; i < len; i++){        if (b.indexOf(a[i]) === -1){            res.push(a[i]);        }    }    for(var j = 0, len = b.length; j < len; j++){        if (a.indexOf(b[j]) === -1){            res.push(b[j]);        }    }    return res;}alert(cha(a, b));//1,4,5