locutus/php/strings/chr.js

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

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.chr = chr;
function chr(codePt) {
    //      discuss at: https://locutus.io/php/chr/
    // parity verified: PHP 8.3
    //     original by: Kevin van Zonneveld (https://kvz.io)
    //     improved by: Brett Zamir (https://brett-zamir.me)
    //          note 1: Unlike PHP (which wraps at 256), this implementation
    //          note 1: supports Unicode code points beyond 255 using surrogates
    //       example 1: chr(75) === 'K'
    //       returns 1: true
    if (codePt > 0xffff) {
        // Create a four-byte string (length 2) since this code point is high
        //   enough for the UTF-16 encoding (JavaScript internal use), to
        //   require representation with two surrogates (reserved non-characters
        //   used for building other characters; the first is "high" and the next "low")
        codePt -= 0x10000;
        return String.fromCharCode(0xd800 + (codePt >> 10), 0xdc00 + (codePt & 0x3ff));
    }
    return String.fromCharCode(codePt);
}