How can I detect if backspace is pressed on the site?
Question
I am currently making a simple online text editor site. And I cannot detect backspace being pressed. Here is the code: HTML
<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" href="cssfile/style.css">
<title> Code Editor </title>
<script src="jsfile/main.js"></script>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body>
<div class="navdiv"></div>
<div id="board" class="board">
</div>
</body>
</html>
js: This is my main code:
document.addEventListener("keypress", function (event) {
console.log(event.key)
if (event.key == "Enter") {
document.getElementById("board").innerText += '\n'
} else {
document.getElementById("board").innerText += event.key
}
});
This is my code and I tried
if(event.key == "Backspace")
But that didn't work.
5 answers
solution1
2 ACCPTED 2021-09-28 14:29:48
You are close.
You are using keypress when you should be using keyup (or keydown if you want to know before the key press is complete).
KeyPress event is invoked only for character (printable) keys, KeyUp and KeyDown events is raised for all including non-printable such as Control, Shift, Alt, BackSpace, etc.
Try this:
document.addEventListener("keyup", function(event) {
console.log(event.key);
if (event.key === "Backspace") {
document.getElementById("board").innerText += '\n'
} else {
document.getElementById("board").innerText += event.key
}
});
solution2
2 2021-09-28 14:30:37
keypress event has been deprecated and there's a change your browser doesn't support it. Use keydown instead.
document.addEventListener("keydown", function (event) {
console.log(event.key)
if (event.key == "Backspace") {
document.getElementById("board").innerText += '\n'
} else {
document.getElementById("board").innerText += event.key
}
});
solution3
1 2021-09-28 14:31:29
The keypress event is deprecated and triggers only when a key press produces a character value. Thus, it is not triggered with the backspace in your case.
You should use the keydown event.
solution4
0 2021-10-30 23:48:05
2021 Update: Use keyup & event.key
❌ Bad
keydownlets you know when the key is pressed down, but this fires before any action takes place.-
event.keyCodeis both difficult to interpret (numbers representing letters and all), and deprecated
✅ Good
keyupfires after the backspace event has happened (ie a character was deleted), just likekeypressevent.keyis both universally supported and not deprecated
<form>
<label>Foo:
<input name="foobar" placeholder="ex: foobar" />
</label>
</form>
document.querySelector('input[name="foobar"]').addEventListener('keyup', function (ev) {
console.log(ev.key);
if ("Backspace" == ev.key) {
console.log("It's a backspace!!");
}
})
solution5
-1 2021-09-28 14:28:41
You can use event.keyCode == 8 .
document.addEventListener("keydown", function(event) { console.log(event.keyCode); if (event.keyCode == 8) { document.getElementById("board").innerText += '\\n' } else { document.getElementById("board").innerText += event.key } });
KeyCode Docs:
https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/keyCode#constants_for_keycode_value
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.