.first()

Reduce the set of matched elements to the first in the set.

Given a jQuery object that represents a set of DOM elements, the .first() method constructs a new jQuery object from the first element in that set.

Consider a page with a simple list on it:

<ul>
  <li>list item 1</li>
  <li>list item 2</li>
  <li>list item 3</li>
  <li>list item 4</li>
  <li>list item 5</li>
</ul>

We can apply this method to the set of list items:

$( "li" ).first().css( "background-color", "red" );

The result of this call is a red background for the first item.

.first()

version added: 1.4

This method does not accept any arguments.

Examples:

Highlight the first span in a paragraph.

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>first demo</title>
  <style>
  .highlight{
    background-color: yellow
  }
  </style>
  <script src="https://code.jquery.com/jquery-1.10.2.js"></script>
</head>
<body>
 
<p>
  <span>Look:</span>
  <span>This is some text in a paragraph.</span>
  <span>This is a note about it.</span>
</p>
 
<script>
$( "p span" ).first().addClass( "highlight" );
</script>
 
</body>
</html>

Links:

http://api.jquery.com/first

doc_jQuery

2016-03-27 13:48:22

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