The meaning of $(this) in jquery

The meaning of $(this) in jquery

jquery is a popular javascript library that provides developers with many convenient API functions, making web development easier and more efficient. $(this) is the most commonly used function in jquery, and it is very important for understanding the use of jquery. This article will explain in detail the usage and significance of the $(this) function.

$(this) is a keyword in jquery, which represents the element currently being operated on. In jquery, this is a pointer to the current element. $(this) can be understood as converting the DOM element pointed to by this into a jQuery object. In jquery, DOM elements cannot use the functions provided by jquery. The DOM elements must be converted into jquery objects before they can be operated. The usage of

$(this) is very simple. It can be used in any jquery event handling function, such as click, mouseover, keydown and other events. In the event handling function, $(this) can replace the element currently being operated on, and then use the functions provided by jquery to operate on it.

For example, if you want to add a click event to a group of list items, every time the user clicks on a list item, you need to add a class style to it. This can be achieved with the following code:

$(function(){
  $('li').on('click', function(){
    $(this).addClass('selected');
  });
});

In this example, $('li') finds all list items and binds them to a click event. When the user clicks on a list item, $(this) represents the list item currently being clicked, and then uses the addClass function to add a selected style to it.

In addition to using $(this) in event handling functions, it can also be used in other jquery functions. For example, in an each loop, $(this) can represent the element currently being processed:

$(function(){
  $('li').each(function(){
    $(this).attr('title', $(this).text());
  });
});

In this example, $('li').each() loops through all list items, and Use $(this) to represent the element currently being processed. Then use the attr function to set a title attribute for it, and the attribute value is the text content of the list item.

Summary: $(this) is a very important keyword in jquery, which represents the element currently being operated on. Using $(this) can make the code more convenient and concise. If you use jquery for web development, then don't hesitate to master the use of $(this).

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