js 判斷數組中是否有某值

    function arrHasValue(v, arr) {
        var output = false;
        for (var i in arr) {
            if (v == arr[i]) {
                output = true;
                return output;
            }
        }
        output = false;
        return output;
    }

var arrs = ['1','2','3'];　　   

console.log(arrHasValue(1,a)); //true