CODEWITHSUNDEEP
node.jsbuffer
Ernest Okot
Ernest Okot

Reputation: 988

Convert NodeJS buffer to integer

I want to generate random numbers using randomBytes in NodeJS. After looking around I found a method that converts buffers to integers;

const integer = parseInt(buffer.toString("hex"), 16)

Is there something wrong with using this method. I've seen other solutions that use buffer.readUIntBE and other similar methods. I'm wondering what advantage they have over the solution above

Upvotes: 6

Views: 16443

Answers (2)

KISHAN KUMAR PATEL
KISHAN KUMAR PATEL

Reputation: 49

Hope you like the following solution for number to byte conversion and byte to number:

const {Int64BE} = require("int64-buffer");

let time = (new Date()).getTime();
console.log("Original Number : " + time);

// Number to buffer conversion ///////////
let timeBuffer = new Int64BE(time); 
let buf = timeBuffer.toBuffer();
console.log("Buffer Format : " + JSON.stringify(buf));

//From buffer to number - approach 1 ///////////////
let num = new Int64BE(buf)
num = num.toNumber();
console.log("Back to Nnumber using aproach 1: " + num);

//from buffer to number - approach 2 ///////////////
let timestamp = Buffer.from( buf.slice(0, 4)).readUInt32BE();
timestamp = 4294967296 * timestamp + Buffer.from( buf.slice(4, 8) ).readUInt32BE();
console.log("Back to Nnumber using aproach 2: " + timestamp);

Upvotes: 0

stefanobaghino
stefanobaghino

Reputation: 12804

Maybe not necessarily wrong, but converting a buffer to its hexadecimal string representation to then parse it into a number seems, to say the least, not very straightforward and unnecessarily resource-consuming.

The buffer read methods mostly perform numeric operations (e.g. here) and should be much less resource-consuming while also, in my opinion, being easier to interpret for whoever reads your code.

function randomUInt32() {
   return crypto.randomBytes(4).readUInt32BE();
}

vs.

function randomUInt32() {
   return parseInt(crypto.randomBytes(4).toString("hex"), 16);
}

Upvotes: 12

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