locutus/python/math/copysign.js

Locutus other languages' standard libraries to JavaScript for fun and educational purposes

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.copysign = copysign;
const signBuffer = new ArrayBuffer(8);
const signView = new DataView(signBuffer);
function hasNegativeSign(value) {
    signView.setFloat64(0, value);
    return (signView.getUint8(0) & 0x80) !== 0;
}
function copysign(x, y) {
    //      discuss at: https://locutus.io/python/copysign/
    // parity verified: Python 3.12
    //     original by: Kevin van Zonneveld (https://kvz.io)
    //          note 1: Returns x with the sign of y
    //       example 1: copysign(1, -2)
    //       returns 1: -1
    //       example 2: copysign(-3, 4)
    //       returns 2: 3
    //       example 3: copysign(5, -0.0)
    //       returns 3: -5
    const magnitude = Math.abs(x);
    return hasNegativeSign(y) ? -magnitude : magnitude;
}