Converting Javascript Key Code to Char and vice versa

Question

I'm working on HTML input filtering, and I have the following situation:

I need to convert keyCodes to chars, but when I'm dealing with Numpad keys I get weird outcome:

String.fromCharCode(96) //should be 0 but I recieve "`"
String.fromCharCode(97) //should be 1 but I recieve "a"
String.fromCharCode(98) //should be 2 but I receive "b"
String.fromCharCode(99) //should be 3 but I recieve "c"
String.fromCharCode(100) //should be 4 but I recieve "d"
String.fromCharCode(101) //should be 5 but I recieve "e"
String.fromCharCode(102) //should be 6 but I recieve "f"
String.fromCharCode(103) //should be 7 but I recieve "g"

From documentation and from event debugging I can see the following mapping:

numpad 0    96
numpad 1    97
numpad 2    98
numpad 3    99
numpad 4    100
numpad 5    101
numpad 6    102
numpad 7    103

link: https://www.cambiaresearch.com/articles/15/javascript-char-codes-key-codes

What am I missing here?

Check out this answer : https://stackoverflow.com/questions/5630918/get-correct-keycode-for-keypadnumpad-keys/42917149#42917149 — sudip, Jan 14 '18 at 22:38
Please show the [MCVE] code you're using, that way we can more easily provide you with a working answer. — David Thomas, Jan 14 '18 at 22:41
https://stackoverflow.com/questions/5630918/get-correct-keycode-for-keypadnumpad-keys — Red Mercury, Jan 14 '18 at 22:45
What Minimal, Complete, and Verifiable example? Just execute String.fromCharCode(103) and you'll get an example — Pavel Durov, Jan 14 '18 at 22:57

score 1 · Answer 1 · answered Jan 14 '18 at 22:39

1

Use the ASCII table to get char codes.

answered Jan 14 '18 at 22:39

Sergey Benzenko

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score 0 · Answer 2 · answered Jan 14 '18 at 22:39

0

Might just be a silly mistake. Charcode you should see is 48-57 for the numbers.

for ( let i = 0; i < 10; i++ ) {
  console.log( String.fromCharCode( 48 + i ) );
}

See man ascii

answered Jan 14 '18 at 22:39

Michael Mikowski

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1
10
21

I meant you might be looking at the wrong numbers for the ascii characters. No offence meant :). – Michael Mikowski Jan 15 '18 at 21:00
Yeah, thanks :) I was confused between keyCodes and ASCII codes (because String.fromCharCode doc isn't mention anything regarding that) – Pavel Durov Jan 16 '18 at 17:28

score 0 · Answer 3 · answered Jan 15 '18 at 09:43

0

Ok, so accordingly to several sources from the web I should do the following logic:

if(keyCode >= 96 && keyCode <= 105){
    keyCode -= 48;
}

Wierd that String.fromCharCode function docs doens't say anything about it :(

answered Jan 15 '18 at 09:43

Pavel Durov

1,287
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Converting Javascript Key Code to Char and vice versa

3 Answers3