JSFiddle - React, Tailwind, and code Playground

by Murat Kezli

HTML

<textarea rows="2" cols="20" id="pPost">mardagz
</textarea> 
<input type="button" id="bbbold" value="clcikMe" />

<input type="button" id="rpcl" value="replace" />
<div id="yaz">

</div>

JavaScript

function buyukharf(textBox) {
    var deger = textBox;
    var specialLetters = { "i": "İ", "ş": "Ş", "ğ": "Ğ", "ü": "Ü", "ö": "Ö", "ç": "Ç", "ı": "I" };
    val = deger.replace(/(([iışğüçö]))/g, function (letter) { return specialLetters[letter]; });
    return val.toUpperCase();
    //$(textBox).val(val.toUpperCase());
}

function kucukharf(textBox) {
    var val = $(textBox).val();
    var letters = { "İ": "i", "I": "ı", "Ş": "ş", "Ğ": "ğ", "Ü": "ü", "Ö": "ö", "Ç": "ç" };
    val = val.replace(/(([İIŞĞÜÇÖ]))/g, function (letter) { return letters[letter]; });
    $(textBox).val(val.toLowerCase());
}

function toTitleCase(str) {
    var specialLetters = { "i": "İ", "ş": "Ş", "ğ": "Ğ", "ü": "Ü", "ö": "Ö", "ç": "Ç", "ı": "I" };
    var letters = { "İ": "i", "I": "ı", "Ş": "ş", "Ğ": "ğ", "Ü": "ü", "Ö": "ö", "Ç": "ç" };
    var arr = str.split(' ');
    for (var i = 0; i < arr.length; i++) {
        arr[i] = arr[i].charAt(0).replace(/(([iışğüçö]))/g, function (letter) { return specialLetters[letter]; }).toUpperCase() + arr[i].substr(1).replace(/(([İIŞĞÜÇÖ]))/g, function (letter) { return letters[letter]; }).toLowerCase();
    }
    return arr.join(" ");
}

var capitalizeAll = function (input) {
    var specialLetters = { "i": "İ", "ş": "Ş", "ğ": "Ğ", "ü": "Ü", "ö": "Ö", "ç": "Ç", "ı": "I" };
    return input.replace(/^./, function (match) {
        return match.replace(/(([iışğüçö]))/g, function (letter) { return specialLetters[letter]; }).toUpperCase();
    });
};

function ilkharfbuyuk(textBox) {
    var val = $(textBox).val();
    $(textBox).val(toTitleCase(val));
}


function getSelectedText() {
    var len =$("#pPost").val().length;
    var start = $("#pPost")[0].selectionStart;
    var end = $("#pPost")[0].selectionEnd;
    var sel = $("#pPost").val().substring(start, end);
    return sel;
}


function bbrep(start, end) {
    var tmpVal = getSelectedText();
    $("#pPost").val($("#pPost").val().replace(tmpVal, start + toTitleCase(tmpVal) +...