Setting functions in jquery

<p>Introduction:

<p>In web development, jQuery is often used as a writing tool for related script code. In the jQuery tool library, there are many callable built-in functions, but these built-in functions are not enough to meet all our needs. So, in many cases, we need to define our own functions. This article will focus on how to set up functions in jQuery.

<p>1. Definition of jQuery plug-ins and functions

<p>jQuery plug-ins are scripts that add additional functions to the jQuery library. They are written by developers and usually contain one or more functions. Developers can extend the jQuery library by creating their own functions. Here is the syntax for defining a jQuery function:

$.fn.functionName = function() {
  //Code to be executed
};

<p> In the above syntax, functionName is the name of the function you want to define. You are free to choose any name. Next, you need to define the operation of the function through a function body. In the function body, you can use all the built-in functions that the jQuery library already has.

<p>For example, the following code defines a jQuery function named customFunction:

$.fn.customFunction = function() {
  $(this).css("background-color", "yellow");
};

<p>In the above code, we use two jQuery functions. The first function is $(this), which selects the current DOM element on which we are calling the function. The second function is css(), which changes the background color of the element.

<p>2. Use custom functions in code

<p>After defining a new jQuery function, we need to call it in code.

<p>For example, the following example demonstrates how to call a defined customFunction function:

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

<p>The above code first waits for the entire page to load, and then adds a single click event handler. When the button is clicked, it calls the customFunction function and applies it to all <p> elements.

<p>3. Definition of plug-in

<p>The definition of jQuery plug-in is very similar to the definition of function. Plug-ins are usually composed of multiple functions that work together to solve a problem.

<p>The following is the syntax for defining a jQuery plug-in:

(function($) {
  $.fn.pluginName = function() {
    //Code to be executed
  };
})(jQuery);

<p>In the above code, pluginName is the name of the plug-in we want to define. We associate a self-executing function with this name. The self-executing function has a parameter $, which is a reference to the jQuery library. Next, we use $.fn to define the plugin. Similar to function definitions, we provide our logical operations in the body of the plugin. Finally, we pass jQuery as a parameter in the self-executing function.

<p>For example, the following code defines a jQuery plugin named customPlugin:

(function($) {
  $.fn.customPlugin = function() {
    $(this).css("background-color", "yellow");
    return this;
  };
})(jQuery);

<p>In the above code, we define a plugin that changes the call The background color of all its elements. We use return this so that plugins can be chained.

<p>4. Use the plug-in in the code

<p>After defining the new jQuery plug-in, we need to use it in the code.

<p>For example, the following example demonstrates how to call a defined customPluginplugin:

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

<p>The above code first waits for the entire page to load, and then adds a single button for the button element. click event handler. When the button is clicked, it calls the customPlugin plugin and applies it to all <p> elements. Next, we chain-called jQuery’s built-in slideUp() function to produce a sliding animation effect.

<p>Conclusion:

<p>In this article, we learned how to define your own functions and plugins in jQuery and explored how to use these functions and plugins in your code. Custom jQuery functions and plugins can help us solve specific problems and improve the readability and maintainability of our code. I hope this article inspired you about jQuery and helped you use it more effectively.

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