We want to develop a jQuery plug-in or simply define our own methods or properties on the object by augmentation. Which of these statements are correct?

Question

Accepted Answer

You can only add:

1. new methods on the object
2. new methods on jQuery class objects returned by the`jQuery()` function
3. pseudo-classes.

Accepted Answer

Consider the code below. The `this.each` value represents the jQuery class object, while the `this` value(same as `value`) in the callback function code `(index,value)` represents an HTML element of the list. So `$(this)` allows to create a jQuery class object(containing only one element, the one represented by`this`), on which can be used the `.html()` method which returns the code HTML of the first item in the list, here `this`.

```javascript
jQuery.fn.display= function(){
  this.each(function(index, value){
    alert($(this).html());
  });
};
$("p").display();

```

Accepted Answer

The code to create a pseudo class that specifies elements that have 5 children(eg for a div: div:five-children) is valid.

```javascript
jquery.extend(jQuery.expr[":"],
 {
   "five-children": function(element, index, matches, set){
      var nb_child= 0;
      for(var node= element. firstChild; node; node= node. next Sibiling){
        if(node. nodeType== 1){
          nb_child++;
        }
      }
      if(nb_child== 5){
        return true;
      } else{
        return false;
      }
    }
);
```

Answer

The code in answer B allows method chaining.

Question from the jQuery test

We want to develop a jQuery plug-in or simply define our own methods or properties on the object by augmentation. Which of these statements are correct?