CODEWITHSUNDEEP
angularjs
Canttouchit
Canttouchit

Reputation: 3159

passing $scope variable to a function in AngularJS

I've been trying to create a generic function in angular that changes a $scope parameters value.

I've been wondering why I cannot pass $scope.var as an argument to a function e.g.:

webApp.controller ('VotesCtrl', function ($scope) {
    $scope.param = 42;

    change($scope.param);
    function change(contextParam) {
      contextParam = (Math.random()*100)+1;
    };
});

When I ran this function $scope.param remains 42.

Is there an alternative besides:

webApp.controller ('VotesCtrl', function ($scope) {
    $scope.param = 42;

    change('param');
    function change(contextParam) {
      $scope[contextParam] = (Math.random()*100)+1;
    };
});

My Plunk

Upvotes: 2

Views: 5266

Answers (1)

Ian Mercer
Ian Mercer

Reputation: 39277

The short answer is "Don't bind to primitive values". See http://stsc3000.github.io/blog/2013/10/26/a-tale-of-frankenstein-and-binding-to-service-values-in-angular-dot-js/

var webApp = angular.module('webApp', []);

//controllers
webApp.controller ('VotesCtrl', function ($scope) {
    $scope.param = { value: 42 };

    change($scope.param);
    function change(contextParam) {
      contextParam.value = (Math.random()*100)+1;
    };
});

Upvotes: 6

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