An in-depth explanation of the meaning and function of the $ symbol in jQuery

Detailed explanation of the meaning and function of the $ symbol in jQuery

In the process of learning jQuery, we often see the $ symbol being widely used in code. The $ symbol is actually jQuery's core identifier, used instead of the full name of jQuery. This article will explain the meaning and function of the $ symbol in detail and provide specific code examples.

1. The meaning of the $ symbol

$ The symbol is a global variable provided by jQuery and can concisely represent jQuery objects. Through the $ symbol, we can quickly call the methods and properties provided by jQuery without having to write the full name of jQuery every time. Therefore, the $ symbol can be said to be a simplified identifier for jQuery, improving the readability and simplicity of the code.

2. The role of the $ symbol

2.1 Selector

$ The symbol can be used together with the selector to quickly select elements in the document. The following is a simple example:

$(document).ready(function() {
    $("button").click(function() {
        $("p").hide();
    });
});

In the above code, the $ symbol represents the jQuery object, and the button and segment elements are selected through the selectors $("button") and $("p") respectively. , and hides all paragraph elements on button click.

2.2 DOM operations

$ symbols can also perform DOM operations, such as adding, deleting, inserting elements, etc. For example:

$(document).ready(function() {
    $("button").click(function() {
        $("p").append(" <b>Appended text</b>.");
    });
});

In the above code, all paragraph elements are selected through the $ symbol, and a piece of text is added at the end of each paragraph when the button is clicked.

2.3 Event processing

$ symbols can simplify the process of event processing and can easily bind event listeners, as shown below:

$(document).ready(function() {
    $("button").click(function() {
        alert("Button clicked!");
    });
});

In the above code, through The $ symbol selects the button element and pops up a tooltip when the button is clicked.

Summary

Through the above content, we can see that the $ symbol plays a very important role in jQuery. It not only simplifies code writing, but also improves code readability and flexibility. In actual development, the $ symbol has become the representative symbol of jQuery and has become an essential tool for almost every jQuery developer. I hope this article will have a clear understanding of the meaning and function of the $ symbol and help readers better master jQuery usage skills.

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