locutus/esm/golang/url/ParseQuery.js

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

import { QueryUnescape } from "./QueryUnescape.js";
export function ParseQuery(query) {
    //      discuss at: https://locutus.io/golang/url/ParseQuery
    // parity verified: Go 1.23
    //     original by: Kevin van Zonneveld (https://kvz.io)
    //          note 1: Parses URL-encoded key/value pairs into arrays per key.
    //       example 1: ParseQuery('a=1&b=2&b=3')
    //       returns 1: {a: ['1'], b: ['2', '3']}
    //       example 2: ParseQuery('q=go+lang&x=%2B')
    //       returns 2: {q: ['go lang'], x: ['+']}
    //       example 3: ParseQuery('empty=&flag')
    //       returns 3: {empty: [''], flag: ['']}
    const raw = String(query);
    if (raw === '') {
        return {};
    }
    const out = {};
    const pairs = raw.split('&');
    for (const pair of pairs) {
        if (pair === '') {
            continue;
        }
        const separator = pair.indexOf('=');
        const keyRaw = separator >= 0 ? pair.slice(0, separator) : pair;
        const valueRaw = separator >= 0 ? pair.slice(separator + 1) : '';
        const key = QueryUnescape(keyRaw);
        const value = QueryUnescape(valueRaw);
        const existing = out[key];
        if (existing) {
            existing.push(value);
        }
        else {
            out[key] = [value];
        }
    }
    return out;
}