Convert English digits to persian digits or persian words

enDigitsToFa.js

// with thousand separator
const convertToPersianDigits = (number) => number.toLocaleString('fa-IR')

// without thousand separator
const convertToPersianDigitsNoDec = (string) => string.toLocaleString('fa-IR', {useGrouping: false})

// Keep non numeric characters intact and convert english digits to persian
function convertToPersianDigits(input) {
    // Convert input to a string
    input = input.toString();

    // Define arrays for English and Persian digits
    const englishDigits = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9'];
    const persianDigits = ['۰', '۱', '۲', '۳', '۴', '۵', '۶', '۷', '۸', '۹'];

    // Convert each character in the input string
    const result = input.split('').map(char => {
        // Check if the character is an English digit
        if (englishDigits.includes(char)) {
            // Replace English digit with its Persian counterpart
            return persianDigits[englishDigits.indexOf(char)];
        } else {
            // Keep non-numeric characters intact
            return char;
        }
    });

    // Join the characters back into a string and return
    return result.join('');
}

// remove none numeric characters and convert to persian digits
function toFarsiNumber(n) {
    const farsiDigits = ['۰', '۱', '۲', '۳', '۴', '۵', '۶', '۷', '۸', '۹'];
    return n
        .toString()
        .split('')
        .map(x => farsiDigits[x])
        .join('');
}

// english digits to persian string (wordify number)
function enNumToFaWords(str) {
    var delimiter, digit, i, iThree, numbers, parts, result, resultThree, three;
    if (!isFinite(str)) {
        return "";
    }
    if (typeof str !== "string") {
        str = str.toString();
    }
    parts = ["", "هزار", "میلیون", "میلیارد", "هزار میلیارد", "کوادریلیون", "کویینتیلیون", "سکستیلیون"];
    if (str.toString().length >= 13 && str.toString().length <= 15) {
        numberSlices = str.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ",");
        numberSlices = numberSlices.split(",");
        sliceToCheck = numberSlices[1];
        if (sliceToCheck !== "000") {
            parts = ["", "هزار", "میلیون", "میلیارد", "هزار", "کوادریلیون", "کویینتیلیون", "سکستیلیون"];
        }
    }
    numbers = {
        0: ["", "صد", "دویست", "سیصد", "چهارصد", "پانصد", "ششصد", "هفتصد", "هشتصد", "نهصد"],
        1: ["", "ده", "بیست", "سی", "چهل", "پنجاه", "شصت", "هفتاد", "هشتاد", "نود"],
        2: ["", "یک", "دو", "سه", "چهار", "پنج", "شش", "هفت", "هشت", "نه"],
        two: ["ده", "یازده", "دوازده", "سیزده", "چهارده", "پانزده", "شانزده", "هفده", "هجده", "نوزده"],
        zero: "صفر",
    };
    delimiter = " و ";
    // debugger;
    str = str
        .split("")
        .reverse()
        .join("")
        .replace(/\d{3}(?=\d)/g, "$&,")
        .split("")
        .reverse()
        .join("")
        .split(",")
        .map(function (str) {
            return Array(4 - str.length).join("0") + str;
        });
    result = (function () {
        var results;
        results = [];
        for (iThree in str) {
            three = str[iThree];
            resultThree = (function () {
                var j, len, results1;
                results1 = [];
                for (i = j = 0, len = three.length; j < len; i = ++j) {
                    digit = three[i];
                    if (i === 1 && digit === "1") {
                        results1.push(numbers.two[three[2]]);
                    } else if ((i !== 2 || three[1] !== "1") && numbers[i][digit] !== "") {
                        results1.push(numbers[i][digit]);
                    } else {
                        continue;
                    }
                }
                return results1;
            })();
            resultThree = resultThree.join(delimiter);
            results.push(resultThree + " " + parts[str.length - iThree - 1]);
        }
        return results;
    })();
    result = result.filter(function (x) {
        return x.trim() !== "";
    });
    //ali
    var copystr = str;
    copystr.splice(str.length - 1, 1);
    var copyresult = result;
    //find 000 elements
    //must delete indexes
    var indexes = [];
    for (var i = 0; i < copystr.length; i++) {
        if (copystr[i] == "000") {
            indexes.push(i);
        }
    }
    //set elementsto -1 for delete later
    // debugger;
    for (var i = 0; i < indexes.length; i++) {
        result[indexes[i]] = "-1";
    }

    var length = result.length;
    while (length--) {
        if (result[length] == "-1") {
            result.splice(length, 1);
        }
    }

    //end ali

    result = result.join(delimiter).trim();
    if (result !== "") {
        return result;
    } else {
        return numbers.zero;
    }
}