Removing ng-class - angularjs

Question

How can I remove ng-class in angular js.
Here is my example code
<form name="myform" ng-class="plus">
//...
<button ng-click="save()">click</button>
</form>
and what I tried but does not work
$scope.add_page = function(){
$scope.myform.removeClass(plus);//what i try but not work
}
any suggest how to removed class or remove attribute ?

Answer 1

Just change it like this
<form name="myform" ng-class="{plus?'plus':''}" ng-init="plus=true">
//...
<button ng-click="save()">click</button>
</form>
and then in controller
$scope.plus=true;
$scope.add_page = function(){
$scope.plus=false;//what i try but not work
}

Answer 2

You can try the below method
<form name="myform" ng-app="myApp" ng-controller="myCtrl">
<div ng-class="plus">with class </div>
<button ng-click="clickme()">
click me to remove class
</button>
</form>
Js
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
$scope.plus="plus";
$scope.clickme=function(){
$scope.plus="";
}
});
CSS
.plus{
background-color:red;
}
Working demo
Note :
You can do the same thing using other methods also.
1) Simply create a class using class instead of ng-class. ng-class is not required here, and then remove it by getting the particular element using id or via event
2) Angularjs is maid on top of javascript only so you can use any of the javascript syntax in angularjs(not a good practice)to remove class .