How to check the existence of key in an object using AngularJS ?
Given an object containing (key, value) pair and the task is to check whether a key exists in an object or not using AngularJS.
Approach: The approach is to use the in operator to check whether a key exists in object or not. In first example the key “Prop_1” is input and it exists in the object. In the second example the user can check which key they want to check for existence.
Example 1:
<!DOCTYPE HTML> <html> <head> <script src= "//ajax.googleapis.com/ajax/libs/angularjs/1.2.13/angular.min.js"> </script> <script> var myApp = angular.module("app", []); myApp.controller("controller", function ($scope) { $scope.obj1 = { "Prop_1": 1, "Prop_2": 2, "Prop_3": 3 }; $scope.res = ''; $scope.textval = "Prop_1"; $scope.checkK = function () { var txtVal = $scope.textval; if (!(txtVal in $scope.obj1)) { $scope.res = "Key not Exists."; } else { $scope.res = "Key Exists"; } } }); </script> </head> <body style="text-align:center;"> <h1 style="color:green;"> GeeksForGeeks </h1> <p> Check if a key exists in an object in AngularJS </p> <div ng-app="app"> <div ng-controller="controller"> Object - {{obj1}}<br><br> Enter the key: <input type="text" ng-model="textval"> <br><br> <button ng-click="checkK()"> Check here</button> <br><br> {{res}}<br> </div> </div> </body> </html> |
Output:
Example 2:
<!DOCTYPE HTML> <html> <head> <script src= "//ajax.googleapis.com/ajax/libs/angularjs/1.2.13/angular.min.js"> </script> <script> var myApp = angular.module("app", []); myApp.controller("controller", function ($scope) { $scope.obj1 = { "Prop_1": 1, "Prop_2": 2, "Prop_3": 3 }; $scope.res = ''; $scope.textval = ""; $scope.checkK = function () { var txtVal = $scope.textval; if (!(txtVal in $scope.obj1)) { $scope.res = "Key not Exists."; } else { $scope.res = "Key Exists"; } } }); </script> </head> <body style="text-align:center;"> <h1 style="color:green;"> GeeksForGeeks </h1> <p> Check if a key exists in an object in AngularJS </p> <div ng-app="app"> <div ng-controller="controller"> Object - {{obj1}}<br><br> Enter the key: <input type="text" ng-model="textval"> <br><br> <button ng-click="checkK()"> Check here</button> <br><br> {{res}}<br> </div> </div> </body> </html> |
Output:
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