What\'s the Difference Between KeyDown, KeyUp, and the Deprecated KeyPress Events?

Understanding KeyPress, KeyUp, and KeyDown Events

To distinguish between keypress, keyup, and keydown events, consider them analogous to mouse events: click, mouseup, and mousedown. The onKeyDown event triggers when you press any key, similar to mousedown.

OnKeyUp triggers when you release a key, like mouseup. It's important to understand that you can release a key (onKeyUp) without first pressing it (onKeyDown). This often occurs when keys are held down and then released eventually, triggering both events.

OnKeyPress, however, is now deprecated and should be replaced with onKeyDown. It once combined onKeyDown and onKeyUp events, behaving similarly to onKeyPress, but this usage is no longer recommended.

Exception for Webkit Browsers

WebKit-based browsers introduce an additional event: TextInput. This event occurs between keypress and keyup, specifically when text is entered. The sequence of events in WebKit browsers is as follows:

• Keydown
• Keypress
• TextInput
• Keyup

Interactive Demonstration

To visualize the event firing sequence, try the following code snippet:

window.addEventListener("keyup", log);
window.addEventListener("keypress", log);
window.addEventListener("keydown", log);

function log(event) {
  console.log(event.type);
}

This code logs the type of event to the console when each key is pressed or released. It will help you understand the differences and ordering of these events.

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