In one of the controllers of my angular application i have a variable set as follows.

SomeService.get({}, function(data){
    // this sets xyz as the list of the data retrieved 
    // from the resource within the controllers scope
    $scope.xyz = data.objects;    
});

Now $scope.xyz looks something like

[
    0: {id: 1, ...more data here ...},
    1: {id: 2, ...more data here ...},
    2: {id: 3, ...more data here ...},
    3: {id: 4, ...more data here ...},
    4: {id: 5, ...more data here ...},
    5: {id: 6, ...more data here ...},
]

What i am trying to do is get an object within xyz using the id property (not the list index). I am aware that I can iterate over the array as follows.

angular.forEach($scope.xyz, function(obj){ return obj.id == 1;});

but is there a way I can do it without looping over the list ?

In one of the controllers of my angular application i have a variable set as follows.

SomeService.get({}, function(data){
    // this sets xyz as the list of the data retrieved 
    // from the resource within the controllers scope
    $scope.xyz = data.objects;    
});

Now $scope.xyz looks something like

[
    0: {id: 1, ...more data here ...},
    1: {id: 2, ...more data here ...},
    2: {id: 3, ...more data here ...},
    3: {id: 4, ...more data here ...},
    4: {id: 5, ...more data here ...},
    5: {id: 6, ...more data here ...},
]

What i am trying to do is get an object within xyz using the id property (not the list index). I am aware that I can iterate over the array as follows.

angular.forEach($scope.xyz, function(obj){ return obj.id == 1;});

but is there a way I can do it without looping over the list ?

• javascript
• angularjs

• Check the answer to this question. The remendation is to use the jQuery grep function. – ckersch Commented Mar 14, 2013 at 14:02
• Are you trying to go without underscore/lo-dash or similar utility belts? – Stewie Commented Mar 14, 2013 at 14:24
• @Stewie well I am open to options, but it would be good if there is a way without depending on a lib for such a small use case. – Amyth Commented Mar 15, 2013 at 9:07
• Well, Angular does not try to offer such low-level utilities, so this question is all about JavaScript solution for loop-less mapping. For that matter I'd say @Bergi answer is the best you can expect. – Stewie Commented Mar 15, 2013 at 9:44

2 Answers 2

Though this is already answered a year ago, since this is one of the top results in Google, I thought I can add the following suggestion which may be the easiest way to filter. After injecting $filter into your controller,

var result = $filter('filter')($scope.xyz, {id:"1"});

reference: https://docs.angularjs/api/ng/filter/filter

No, you can't really avoid looping (O(n)) unless there are some preconditions met.

• If the array is sorted by id, you can use a binary search algorithm (O(log n)).
• If the array index always corresponds to the id-1 (or some similar simple formula), you can directly access it in O(1).

If those conditions are not fulfilled initially, but you need to access the items by id multiple times, it could be helpful to bring them in that form (sorting/building a hash map).