Setting ngTrueValue and ngFalseValue to numbers

You can use ngChecked, If the expression is truthy, then special attribute "checked" will be set on the element

<input type="checkbox"     ng-model="checkbox"     ng-true-value="1"     ng-false-value="0"     ng-checked="checkbox == 1" />

And you can use $scope.$watch to convert it to number

$scope.$watch(function(){    return $scope.checkbox;}, function(){    $scope.checkbox = Number($scope.checkbox);    console.log($scope.checkbox, typeof $scope.checkbox);},true);

DEMO

I have created directive for that, seems to work fine:

angular.module('app').directive('cdTrueValue', [function() {  return {    restrict: 'A',    require: 'ngModel',    link: function(scope, element, attrs, ngModel) {      ngModel.$parsers.push(function(v){        return v ? scope.$eval(attrs.cdTrueValue) : scope.$eval(attrs.cdFalseValue);      });      ngModel.$formatters.push(function(value) {          return value === scope.$eval(attrs.cdTrueValue);      });    }  };}]);

Usage:

<input type="checkbox" ng-model="checkbox" cd-true-value="1" cd-false-value="0" />

DEMO

HTML attributes do not have any types. They can not contain anything else, then a string, so it is always a string. End of story.

You can not differentiate between between 1 and "1" in an HTML attribute. Angular tries to keep up with that, so only strings will work.