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Why are Arrow Keystrokes Not Detected in My JavaScript `checkKey` Function?

Mary-Kate Olsen
Mary-Kate OlsenOriginal
2024-11-24 14:04:14762browse

Why are Arrow Keystrokes Not Detected in My JavaScript `checkKey` Function?

Key Identification and Arrow Key Detection in JavaScript

Detecting keyboard input is essential for many JavaScript applications. While identifying keystrokes is generally straightforward, handling arrow keys presents a unique challenge due to their native scrolling behavior in most browsers. This question explores an issue encountered when using the checkKey function, which successfully captures keypresses but fails to detect arrow keystrokes.

The answer to this issue lies in the specific event types associated with arrow keys. Unlike regular keys, arrow keys only trigger the onkeydown event. Therefore, to capture arrow key input, it is necessary to modify the checkKey function accordingly:

function checkKey(e) {
    var event = window.event ? window.event : e;
    if (event.type === "keydown")  // Check for keydown event
        console.log(event.keyCode)
}

Additionally, the answer provides the corresponding key codes for the arrow keys:

  • left = 37
  • up = 38
  • right = 39
  • down = 40

Utilizing these key codes, developers can easily implement functionality that responds to arrow key presses.

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