JavaScript filter behaving strangely in Angular

Question

I have a function in Angular that's looping through an array:

$scope.things = [{ num: 4 }, { num: 2 }];
$scope.specialThings = [];
$scope.doThings = function() {
    for (var i = 0; i < things.length; i++) {
        // do some things
    }

    $scope.specialThings = $scope.things.filter(function(x) {
        return x.num > 2;
    });

    console.log($scope.specialThings);

};

The for loop is changing, say, the num attribute of items in my things array.

I then use that filter function to isolate a special subset of things . When none of the items match the condition in my filter, console.log prints Array[0] . However, when some items DO match, I get the following:

[Object]
    length: 0
    __proto__: Array[0]

I have no idea what's going on. Help!

Answer 1

It's hard to tell what is the problem without a running example in a jsfiddle but I suspect it's the missing $scope before things.length in your for loop that cause a silent error. So your filter never execute.

Try this:

$scope.doThings = function() {
    for (var i = 0; i < $scope.things.length; i++) {
        // do some things
    }

    $scope.specialThings = $scope.things.filter(function(x) {
        return x.num > 2;
    });

    console.log($scope.specialThings);

};