Let's say I have a hex data stream, which I want to divide into 3-bytes blocks which I need to read as an integer.

For example: given a hex string 01be638119704d4b9a I need to read the first three bytes 01be63 and read it as integer 114275. This is what I got:

var sample = '01be638119704d4b9a';

var buffer = new Buffer(sample, 'hex');

var bufferChunk = buffer.slice(0, 3);

var decimal = bufferChunk.readUInt32BE(0);

The readUInt32BE works perfectly for 4-bytes data, but here I obviously get:

RangeError: index out of range

  at checkOffset (buffer.js:494:11)

  at Buffer.readUInt32BE (buffer.js:568:5)

How do I read 3-bytes as integer correctly?