I want to use an if-statement to run code only if the user types in a letter or a number.
I could use
if (event.keyCode == 48 || event.keyCode == 49 || event.keyCode == 50 || ...) {
// run code
}
Is there an easier way to do this? Maybe some keycodes don't work in all web browsers?
If you want to check a range of letters you can use greater than and less than:
if (event.keyCode >= 48 && event.keyCode <= 57) {
alert('input was 0-9');
}
if (event.keyCode >= 65 && event.keyCode <= 90) {
alert('input was a-z');
}
For a more dynamic check, use a regular expression:
const input = String.fromCharCode(event.keyCode);
if (/[a-zA-Z0-9-_ ]/.test(input)) {
alert('input was a letter, number, hyphen, underscore or space');
}
See the MDC documentation for the keyCode property, which explains the difference between that and the which property and which events they apply to.
