How to use toString(16) in javascript to get byte written in two character

Question

I'm using this function to convert byte array to hex string:

function toHexString(bytes)
 {
  return bytes.map(function (byte)
   {
    return (byte & 0xFF).toString(16)
   }).join('')
 }

The issue is that function write bytes <=15 (F in hex) in one character for example:

10 --> A (but i want to write 0A)

Any Ideas?

score 2 · Accepted Answer · edited Nov 17 '15 at 18:42

2

If byte is below 16, toString(16) returns one character, so you have to prepend the desired zero. Else if byte is 16 or more, you may use your original code, because toString(16) returns two characters.

if (byte < 16)
    return '0' + byte.toString(16);
else
    ...

edited Nov 17 '15 at 18:42

Don't Panic

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answered Nov 17 '15 at 15:21

Welcome to StackOverflow! Please add some explanation to your code: why does it works? What should it do? – ebram khalil Nov 17 '15 at 15:45

score 0 · Answer 2 · edited Nov 17 '15 at 16:52

0

You can do something like this:

function toHexString(bytes) {
    var result = bytes.map(function (byte) {
    if(byte>15)
        return (byte & 0xFF).toString(16)
    else
        return '0'+(byte & 0xFF).toString(16)
     }).join('')
}

Just check the byte value if it's greater than 15 if not add 0 to the result.

edited Nov 17 '15 at 16:52

chris Frisina

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answered Nov 17 '15 at 15:19

manecosta

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That works just when I've one byte to convert not for byte array but I solve this like so: if(byte>15) return (byte & 0xFF).toString(16) else return '0'+(byte & 0xFF).toString(16) – Abdessamad Doughri Nov 17 '15 at 15:33

How to use toString(16) in javascript to get byte written in two character

2 Answers2