Guide to retrieving the second value variable in an array based on the selected dropdown option within a controller

Question

Guide to retrieving the second value variable in an array based on the selected dropdown option within a controller

In my controller, I am trying to extract the second value in an array list that a user selects from a dropdown so that I can perform mathematical operations on it.

$scope.dropdown = [
{name:'Name', value:'123'}]

When a user chooses "Name" from the dropdown, I need to retrieve the value '123'. While I know how to do this on the front-end using:

<p> {{dropdown.value}} </p>

I am struggling to achieve the same in the controller.

I have attempted:

var variable = $scope.dropdown.value;
var variable = $scope.dropdown[0].value;
var variable = $scope.dropdown.value[0];

Unfortunately, none of these methods seem to work.

Here is a snippet of what I am currently working with:

 $scope.input1 = "";

 var rate = 2;

 $scope.dropdown = [
  {name:'Name', value:'123'}
 ];

 var activities = (Number($scope.input1) * $scope.dropdownSelection.value * rate) / 2;

 console.log(activities);

Essentially, I am trying to perform calculations in the controller based on user inputs and dropdown selections, as well as predefined variables. However, I am unable to retrieve the selected value from the dropdown array.

javascript angularjs arrays angularjs-scope

Answer 1

Answer №1

To implement this functionality in AngularJS, it is recommended to utilize the $filter method within your controller. A sample code snippet for achieving this is shown below:

app.controller('MainCtrl', ['$scope', '$filter', function($scope, $filter) {

    // Define an array of items
    var items = [{ id: "5", country: "UAE" }, { id: "4", country: "India" }];

    // Specify the value to search for
    var id2Search = "4";

    // Perform filtering on the array
    var foundItem = $filter('filter')(items, { id: id2Search }, true)[0];

    // Retrieve the index of the found item
    var index = items.indexOf(foundItem);
}]);

Answer 2

To implement this functionality in AngularJS, it is recommended to utilize the $filter method within your controller. A sample code snippet for achieving this is shown below:

app.controller('MainCtrl', ['$scope', '$filter', function($scope, $filter) {

    // Define an array of items
    var items = [{ id: "5", country: "UAE" }, { id: "4", country: "India" }];

    // Specify the value to search for
    var id2Search = "4";

    // Perform filtering on the array
    var foundItem = $filter('filter')(items, { id: id2Search }, true)[0];

    // Retrieve the index of the found item
    var index = items.indexOf(foundItem);
}]);

Answer 3

Answer №2

If you're trying to determine the value that a user has selected from a dropdown menu populated with an array in the controller, here's a potential solution.

Consider the following code snippet:

var app = angular.module("sampleApp", []);

app.controller("sampleController", ["$scope",
  function($scope) {
    $scope.input1 = 1;
    $scope.dropdownValues = [{
      name: 'Name',
      value: 123
    }, {
      name: 'Name-1',
      value: 456
    }, {
      name: 'Name-2',
      value: 789
    }];

    $scope.dropdownValue = 123;
    var rate = 10;

    $scope.$watch(function() {
      return $scope.dropdownValue
    }, function() {
      $scope.activities = (Number($scope.input1) * $scope.dropdownValue * rate) / 2;
    });

  }
]);

div.value {
  padding-top: 15px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.5.8/angular.min.js"></script>
<div ng-app="sampleApp">
  <div ng-controller="sampleController">
    <select ng-model="dropdownValue">
      <option ng-repeat="item in dropdownValues" ng-value="item.value">
        {{item.name}}
      </option>
    </select>
    <div class="value">
      Selected Value : {{dropdownValue}}
    </div>

    <div>
      Activities : {{activities}}
    </div>
  </div>
</div>

Answer 4

If you're trying to determine the value that a user has selected from a dropdown menu populated with an array in the controller, here's a potential solution.

Consider the following code snippet:

var app = angular.module("sampleApp", []);

app.controller("sampleController", ["$scope",
  function($scope) {
    $scope.input1 = 1;
    $scope.dropdownValues = [{
      name: 'Name',
      value: 123
    }, {
      name: 'Name-1',
      value: 456
    }, {
      name: 'Name-2',
      value: 789
    }];

    $scope.dropdownValue = 123;
    var rate = 10;

    $scope.$watch(function() {
      return $scope.dropdownValue
    }, function() {
      $scope.activities = (Number($scope.input1) * $scope.dropdownValue * rate) / 2;
    });

  }
]);

div.value {
  padding-top: 15px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.5.8/angular.min.js"></script>
<div ng-app="sampleApp">
  <div ng-controller="sampleController">
    <select ng-model="dropdownValue">
      <option ng-repeat="item in dropdownValues" ng-value="item.value">
        {{item.name}}
      </option>
    </select>
    <div class="value">
      Selected Value : {{dropdownValue}}
    </div>

    <div>
      Activities : {{activities}}
    </div>
  </div>
</div>

Guide to retrieving the second value variable in an array based on the selected dropdown option within a controller

Answer №1

Answer №2

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