JavaScript implements shortcut keys

With the continuous development of Web technology, Javascript has become an indispensable part of Web front-end development. Javascript is a weakly typed, object-based (object-oriented), event-driven, interpreted language with cross-platform and cross-browser features. Its application scenarios cover web page interaction, dynamic effects, data verification, security control, etc. .

In addition, Javascript can also be used to implement shortcut keys, which is one of the necessary functions for many web applications. Below we will introduce in detail how to use Javascript to implement shortcut key functions.

1. Capture keyboard input events

In Javascript, we can use the addEventListener() method to listen for keyboard input events. This method can add an event listener to any DOM element and trigger the corresponding event on the element.

For example, for the body element on the web page, we can use the following code to listen for keyboard input events:

document.body.addEventListener('keydown', function(e) {
    console.log(e.keyCode);
});

At this time, when we press any key on the keyboard, the event The listener will be triggered and the keyCode value of the keystroke will be output to the browser console.

2. Determine whether the key press meets the expectations

After capturing the keyboard input event, we need to determine whether the key press meets the shortcut key we set. When judging, we mainly need to use keyCode or key attribute to obtain the character encoding or character value of the key.

For example, for the shortcut key Ctrl C, we can use the following code to determine whether it is pressed:

document.body.addEventListener('keydown', function(e) {
    if (e.keyCode === 67 && e.ctrlKey) {
        console.log('Ctrl+C被按下');
    }
});

In this code, we obtain the character encoding of the key through the keyCode attribute. Whether it is the encoding value of character 'C' 67, and determine whether the Ctrl key is also pressed at the same time through the ctrlKey attribute.

3. Perform corresponding operations

After confirming that the shortcut key is pressed, we still need to perform corresponding operations. You can decide which operations need to be performed based on actual needs.

For example, for the shortcut key Ctrl C, we can use the following code to implement the copy function:

document.body.addEventListener('keydown', function(e) {
    if (e.keyCode === 67 && e.ctrlKey) {
        document.execCommand('copy');
    }
});

In this code, we use the document.execCommand() method to perform the copy operation, This method can take advantage of the browser's built-in functions to implement some basic operations, such as copy, cut, and paste.

In addition, we can also write corresponding operation functions ourselves as needed, and call these operation functions to implement specific operations when capturing shortcut key events.

To sum up, it is very simple to use Javascript to implement shortcut key functions. You only need to monitor the keyboard input events to determine whether they match the shortcut keys we set, and then perform the corresponding operations. The key is to accurately set shortcut keys and corresponding operations according to actual needs to achieve a better user experience and function implementation.

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