CODEWITHSUNDEEP
javascriptangularjscoffeescript
ImpostorIsAsking
ImpostorIsAsking

Reputation: 73

how to detect value null in ng-change in controller

here's my view

md-input-container flex=""
        label Mynumber
        input type="number" ng-model="mynumber" ng-change="checkMynumber(mynumber)" step="0.01" ng-pattern="/^[0-9]+(\.[0-9]{1,2})?$/" string-to-number=""

my controller

$scope.checkMynumber = (number) =>
  if number?
    alert "true"
  else
    alert "false"

when i input my first number it alert True that was right but when i erase my inputed number it keeps alert True. i want to alert false when my input type is null.

Upvotes: 0

Views: 1440

Answers (6)

banabella
banabella

Reputation: 39

I don't understand why almost every answer here is in .js instead .coffee, like in question.. anyway you can imporove your code

  1. ng-model="mynumber" ng-change="checkMynumber(mynumber)" I guess mynumber is your scope variable, so why you are passing this to method? (I don't have full code, but you are using fat arrow there, otherwise I would find reason to pass this as argument)

  2. Your method checkMyNumber can be only like this:

    $scope.checkMynumber = => alert $scope.mynumber? + ""

Upvotes: 0

ImpostorIsAsking
ImpostorIsAsking

Reputation: 73

it because of my directives string-to-number thanks guys its working now

Upvotes: 0

Aswathy Balan
Aswathy Balan

Reputation: 504

 $scope.checkMynumber = function (number) {
   if(number) {
     alert(true)
   } else {
     alert(false)
   }
  }

Check this fiddle https://jsfiddle.net/aswathyb950/9jfww52h/

Upvotes: 2

Rohìt Jíndal
Rohìt Jíndal

Reputation: 27222

DEMO

var myApp = angular.module('myApp',[]);
myApp.controller('MyCtrl', ['$scope', function($scope) {
  $scope.checkMynumber = function(number) {
    number ? alert("true") : alert("false");  
  }
}]);
<div ng-app="myApp" ng-controller="MyCtrl">
 <input type="number" ng-model="mynumber" ng-change="checkMynumber(mynumber)" step="0.01" ng-pattern="/^[0-9]+(\.[0-9]{1,2})?$/" string-to-number="">
</div>

Upvotes: 1

Sachila Ranawaka
Sachila Ranawaka

Reputation: 41447

remove the ternary operator and stick with the if else conditions 

angular.module("app",[])
.controller("ctrl",function($scope){
$scope.checkMynumber = function(number) {
  if (number)
    alert("true")
  else
    alert ("false")
    
}

})
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="app" ng-controller="ctrl">
 <input type="number" ng-model="mynumber" ng-change="checkMynumber(mynumber)" step="0.01" ng-pattern="/^[0-9]+(\.[0-9]{1,2})?$/" string-to-number="">
</div>

Upvotes: 1

Nair Athul
Nair Athul

Reputation: 821

You can use

$scope.checkMynumber = function(number){ if (number!= null) alert "true" else alert "false" }

Upvotes: 1

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