locutus/esm/php/strings/soundex.js

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

export function soundex(str) {
    //      discuss at: https://locutus.io/php/soundex/
    // parity verified: PHP 8.3
    //     original by: Jonas Raoni Soares Silva (https://www.jsfromhell.com)
    //     original by: Arnout Kazemier (https://www.3rd-Eden.com)
    //     improved by: Jack
    //     improved by: Kevin van Zonneveld (https://kvz.io)
    //     bugfixed by: Onno Marsman (https://twitter.com/onnomarsman)
    //     bugfixed by: Kevin van Zonneveld (https://kvz.io)
    //        input by: Brett Zamir (https://brett-zamir.me)
    //      revised by: Rafał Kukawski (https://blog.kukawski.pl)
    //       example 1: soundex('Kevin')
    //       returns 1: 'K150'
    //       example 2: soundex('Ellery')
    //       returns 2: 'E460'
    //       example 3: soundex('Euler')
    //       returns 3: 'E460'
    const input = String(str).toUpperCase();
    if (!input) {
        return '';
    }
    const sdx = [0, 0, 0, 0];
    const m = {
        B: 1,
        F: 1,
        P: 1,
        V: 1,
        C: 2,
        G: 2,
        J: 2,
        K: 2,
        Q: 2,
        S: 2,
        X: 2,
        Z: 2,
        D: 3,
        T: 3,
        L: 4,
        M: 5,
        N: 5,
        R: 6,
    };
    let i = 0;
    let s = 0;
    let p = 0;
    let c = input.charAt(i++);
    while (c && s < 4) {
        const j = m[c];
        if (j) {
            if (j !== p) {
                sdx[s++] = p = j;
            }
        }
        else {
            s += Number(i === 1);
            p = 0;
        }
        c = input.charAt(i++);
    }
    sdx[0] = input.charAt(0);
    return sdx.join('');
}