docs(ngClass): updated the example with string, map and array syntax

Closes #3084

Author: xjamundx

src/ng/directive/ngClass.js

@@ -93,7 +93,66 @@ function classDirective(name, selector) {
  *   names of the properties whose values are truthy will be added as css classes to the
  *   element.
  *
- * @example
+ * @example Example that demostrates basic bindings via ngClass directive.
+   <example>
+     <file name="index.html">
+       <p ng-class="{strike: strike, bold: bold, red: red}">Map Syntax Example</p>
+       <input type="checkbox" ng-model="bold"> bold
+       <input type="checkbox" ng-model="strike"> strike
+       <input type="checkbox" ng-model="red"> red
+       <hr>
+       <p ng-class="style">Using String Syntax</p>
+       <input type="text" ng-model="style" placeholder="Type: bold strike red">
+       <hr>
+       <p ng-class="[style1, style2, style3]">Using Array Syntax</p>
+       <input ng-model="style1" placeholder="Type: bold"><br>
+       <input ng-model="style2" placeholder="Type: strike"><br>
+       <input ng-model="style3" placeholder="Type: red"><br>
+     </file>
+     <file name="style.css">
+       .strike {
+         text-decoration: line-through;
+       }
+       .bold {
+           font-weight: bold;
+       }
+       .red {
+           color: red;
+       }
+     </file>
+     <file name="scenario.js">
+       it('should let you toggle the class', function() {
+
+         expect(element('.doc-example-live p:first').prop('className')).not().toMatch(/bold/);
+         expect(element('.doc-example-live p:first').prop('className')).not().toMatch(/red/);
+
+         input('bold').check();
+         expect(element('.doc-example-live p:first').prop('className')).toMatch(/bold/);
+
+         input('red').check();
+         expect(element('.doc-example-live p:first').prop('className')).toMatch(/red/);
+       });
+
+       it('should let you toggle string example', function() {
+         expect(element('.doc-example-live p:nth-of-type(2)').prop('className')).toBe('');
+         input('style').enter('red');
+         expect(element('.doc-example-live p:nth-of-type(2)').prop('className')).toBe('red');
+       });
+
+       it('array example should have 3 classes', function() {
+         expect(element('.doc-example-live p:last').prop('className')).toBe('');
+         input('style1').enter('bold');
+         input('style2').enter('strike');
+         input('style3').enter('red');
+         expect(element('.doc-example-live p:last').prop('className')).toBe('bold strike red');
+       });
+     </file>
+   </example>
+
+   ## Animations
+
+   Example that demostrates how addition and removal of classes can be animated.
+
    <example animations="true">
      <file name="index.html">
       <input type="button" value="set" ng-click="myVar='my-class'">