locutus/esm/php/array/in_array.js

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

export function in_array(needle, haystack, argStrict) {
    //  discuss at: https://locutus.io/php/in_array/
    // original by: Kevin van Zonneveld (https://kvz.io)
    // improved by: vlado houba
    // improved by: Jonas Sciangula Street (Joni2Back)
    //    input by: Billy
    // bugfixed by: Brett Zamir (https://brett-zamir.me)
    //   example 1: in_array('van', ['Kevin', 'van', 'Zonneveld'])
    //   returns 1: true
    //   example 2: in_array('vlado', {0: 'Kevin', vlado: 'van', 1: 'Zonneveld'})
    //   returns 2: false
    //   example 3: in_array(1, ['1', '2', '3'])
    //   example 3: in_array(1, ['1', '2', '3'], false)
    //   returns 3: true
    //   returns 3: true
    //   example 4: in_array(1, ['1', '2', '3'], true)
    //   returns 4: false
    const strict = !!argStrict;
    // we prevent the double check (strict && arr[key] === ndl) || (!strict && arr[key] === ndl)
    // in just one for, in order to improve the performance
    // deciding wich type of comparation will do before walk array
    if (Array.isArray(haystack)) {
        if (strict) {
            for (const key in haystack) {
                if (haystack[Number(key)] === needle) {
                    return true;
                }
            }
        }
        else {
            for (const key in haystack) {
                // biome-ignore lint/suspicious/noDoubleEquals: non-strict comparison intended
                if (haystack[Number(key)] == needle) {
                    return true;
                }
            }
        }
    }
    else if (strict) {
        for (const key in haystack) {
            if (haystack[key] === needle) {
                return true;
            }
        }
    }
    else {
        for (const key in haystack) {
            // biome-ignore lint/suspicious/noDoubleEquals: non-strict comparison intended
            if (haystack[key] == needle) {
                return true;
            }
        }
    }
    return false;
}