Parse HEX float

Question

I have integer, for example, 4060.

How I can get HEX float (\x34\xC8\x7D\x45) from it?

JS hasn't float type, so I don't know how to do this conversion.

Thank you.

I think I'm missing something obvious, but you have an integer; there is no decimal portion (except an implicit `0`). What are you trying to do? — David Thomas, May 17 '13 at 15:17
Anyone who voted for "duplicate", please learn about IEEE 754 formats...voted to reopen. — robertklep, May 17 '13 at 16:48

robertklep · Answer 1 · 2017-11-03T12:23:09.753

7

If you want a hex string, try this:

> var b = new Buffer(4);
> b.writeFloatLE(4060, 0)
> b.toString('hex')
'00c07d45'

And the other way (using your input):

> Buffer('34C87D45', 'hex').readFloatLE(0)
4060.5126953125

UPDATE: new Buffer(size) has been deprecated, but it's easily replaced by Buffer.alloc(size):

var b = Buffer.alloc(4);

edited Nov 03 '17 at 12:23

answered May 17 '13 at 15:51

robertklep

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It can also read doubles in big or little endian. Thanks, very helpful. – BHP Mar 14 '14 at 17:32

score 2 · Accepted Answer · answered Oct 27 '16 at 16:11

The above answer is no longer valid. Buffer has been deprecated (see https://nodejs.org/api/buffer.html#buffer_new_buffer_size).

New Solution:

function numToFloat32Hex(v,le)
{
    if(isNaN(v)) return false;
    var buf = new ArrayBuffer(4);
    var dv  = new DataView(buf);
    dv.setFloat32(0, v, true);
    return ("0000000"+dv.getUint32(0,!(le||false)).toString(16)).slice(-8).toUpperCase();
}

For example:

numToFloat32Hex(4060,true) // returns "00C07D45"
numToFloat32Hex(4060,false) // returns "457DC000"

Tested in Chrome and Firefox

`Buffer` hasn't been deprecated – robertklep Nov 03 '17 at 12:23 — robertklep, Nov 03 '17 at 12:23

Parse HEX float

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