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javascript32-bit

Converting 32-bit unsigned little endian to integer in javascript

I have an array of 4 bytes. 32-bit unsigned little endian.

[ 123, 1, 0, 0]

I need help converting this to an integer. I tried below with no luck:

let arr = [ 123, 1, 0, 0 ];
let uint = new Uint32Array(arr);
console.log('INT :', uint);
Solution

  • There are two ways:

    If you know your browser is also little endian (almost always true these days), then you can do it like this:

    const bytes = new Uint8Array([123, 1, 0, 0]);
const uint = new Uint32Array(bytes.buffer)[0];
console.log(uint);

    If you think your browser might be running in a big endian environment and you need to do proper endian conversion, then you do this:

    const bytes = new Uint8Array([123, 1, 0, 0]);
const dv = new DataView(bytes.buffer);
const uint = dv.getUint32(0, /* little endian data */ true);
console.log(uint);