freeCodeCamp/curriculum/challenges/chinese/03-front-end-libraries/jquery/target-a-specific-child-of-an-element-using-jquery.md

---
id: bad87fee1348bd9aed108826
title: Target a Specific Child of an Element Using jQuery
challengeType: 6
forumTopicId: 18315
required:
  - 
    link: 'https://cdnjs.cloudflare.com/ajax/libs/animate.css/3.2.0/animate.css'
dashedName: target-a-specific-child-of-an-element-using-jquery
---

# --description--

You've seen why id attributes are so convenient for targeting with jQuery selectors. But you won't always have such neat ids to work with.

Fortunately, jQuery has some other tricks for targeting the right elements.

jQuery uses CSS Selectors to target elements. The `target:nth-child(n)` CSS selector allows you to select all the nth elements with the target class or element type.

Here's how you would give the third element in each well the bounce class:

`$(".target:nth-child(3)").addClass("animated bounce");`

Make the second child in each of your well elements bounce. You must select the elements' children with the `target` class.

# --hints--

The second element in your `target` elements should bounce.

```js
assert(
  $('.target:nth-child(2)').hasClass('animated') &&
    $('.target:nth-child(2)').hasClass('bounce')
);
```

Only two elements should bounce.

```js
assert($('.animated.bounce').length === 2);
```

You should use the `:nth-child()` selector to modify these elements.

```js
assert(code.match(/\:nth-child\(/g));
```

You should only use jQuery to add these classes to the element.

```js
assert(
  code.match(/\$\(".target:nth-child\(2\)"\)/g) ||
    code.match(/\$\('.target:nth-child\(2\)'\)/g) ||
    code.match(/\$\(".target"\).filter\(":nth-child\(2\)"\)/g) ||
    code.match(/\$\('.target'\).filter\(':nth-child\(2\)'\)/g)
);
```

# --seed--

## --seed-contents--

```html
<script>
  $(document).ready(function() {
    $("#target1").css("color", "red");
    $("#target1").prop("disabled", true);
    $("#target4").remove();
    $("#target2").appendTo("#right-well");
    $("#target5").clone().appendTo("#left-well");
    $("#target1").parent().css("background-color", "red");
    $("#right-well").children().css("color", "orange");

  });
</script>

<!-- Only change code above this line -->

<div class="container-fluid">
  <h3 class="text-primary text-center">jQuery Playground</h3>
  <div class="row">
    <div class="col-xs-6">
      <h4>#left-well</h4>
      <div class="well" id="left-well">
        <button class="btn btn-default target" id="target1">#target1</button>
        <button class="btn btn-default target" id="target2">#target2</button>
        <button class="btn btn-default target" id="target3">#target3</button>
      </div>
    </div>
    <div class="col-xs-6">
      <h4>#right-well</h4>
      <div class="well" id="right-well">
        <button class="btn btn-default target" id="target4">#target4</button>
        <button class="btn btn-default target" id="target5">#target5</button>
        <button class="btn btn-default target" id="target6">#target6</button>
      </div>
    </div>
  </div>
</div>
```

# --solutions--

```html
<script>
  $(document).ready(function() {
    $("#target1").css("color", "red");
    $("#target1").prop("disabled", true);
    $("#target4").remove();
    $("#target2").appendTo("#right-well");
    $("#target5").clone().appendTo("#left-well");
    $("#target1").parent().css("background-color", "red");
    $("#right-well").children().css("color", "orange");
    $(".target:nth-child(2)").addClass("animated bounce");
  });
</script>

<!-- Only change code above this line -->

<div class="container-fluid">
  <h3 class="text-primary text-center">jQuery Playground</h3>
  <div class="row">
    <div class="col-xs-6">
      <h4>#left-well</h4>
      <div class="well" id="left-well">
        <button class="btn btn-default target" id="target1">#target1</button>
        <button class="btn btn-default target" id="target2">#target2</button>
        <button class="btn btn-default target" id="target3">#target3</button>
      </div>
    </div>
    <div class="col-xs-6">
      <h4>#right-well</h4>
      <div class="well" id="right-well">
        <button class="btn btn-default target" id="target4">#target4</button>
        <button class="btn btn-default target" id="target5">#target5</button>
        <button class="btn btn-default target" id="target6">#target6</button>
      </div>
    </div>
  </div>
</div>
```