locutus/esm/php/strings/str_pad.js

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

export function str_pad(input, padLength, padString, padType) {
    //  discuss at: https://locutus.io/php/str_pad/
    // original by: Kevin van Zonneveld (https://kvz.io)
    // improved by: Michael White (https://getsprink.com)
    //    input by: Marco van Oort
    // bugfixed by: Brett Zamir (https://brett-zamir.me)
    //   example 1: str_pad('Kevin van Zonneveld', 30, '-=', 'STR_PAD_LEFT')
    //   returns 1: '-=-=-=-=-=-Kevin van Zonneveld'
    //   example 2: str_pad('Kevin van Zonneveld', 30, '-', 'STR_PAD_BOTH')
    //   returns 2: '------Kevin van Zonneveld-----'
    let half = '';
    let padToGo;
    const _strPadRepeater = function (s, len) {
        let collect = '';
        while (collect.length < len) {
            collect += s;
        }
        collect = collect.substr(0, len);
        return collect;
    };
    input += '';
    padString = padString !== undefined ? padString : ' ';
    if (padType !== 'STR_PAD_LEFT' && padType !== 'STR_PAD_RIGHT' && padType !== 'STR_PAD_BOTH') {
        padType = 'STR_PAD_RIGHT';
    }
    if ((padToGo = padLength - input.length) > 0) {
        if (padType === 'STR_PAD_LEFT') {
            input = _strPadRepeater(padString, padToGo) + input;
        }
        else if (padType === 'STR_PAD_RIGHT') {
            input = input + _strPadRepeater(padString, padToGo);
        }
        else if (padType === 'STR_PAD_BOTH') {
            half = _strPadRepeater(padString, Math.ceil(padToGo / 2));
            input = half + input + half;
            input = input.substr(0, padLength);
        }
    }
    return input;
}