JSFiddle - React, Tailwind, and code Playground

by Gereltod Gotsbayar

HTML

<input type="button" value="click" id="button" />
<br />
<input />

<div id="log"><div>

JavaScript

$("input").keyup(function(event) {
    
    str = $("input").val();
    var lastChar = str.substr(str .length - 1);
    //var pattern = "абвгдежзийклмноөпрстуүфхцчшщъьюяАБВГДЕЖЗИЙКЛМНОӨПРСТУҮФХЦЧШЩЪЬЮЯ";
    var pattern = "abcdefghijklmnoprstuvwxyzABCDEFGHIJKLMNOPRSTUVWXYZ";
    
    if (pattern.indexOf(lastChar)) {
        alert(pattern.indexOf(lastChar));
    } 
    
});