JSFiddle - React, Tailwind, and code Playground

by this_mong

HTML

<script src="https://code.jquery.com/jquery-3.4.1.min.js"></script>
<input type="tel" onkeydown="return onlyNum(event)" maxlength="12" style="ime-mode:disabled;">

JavaScript

function onlyNum(event) {
    event = event || window.event;
    var key = (event.which) ? event.which : event.keyCode;
    if( ( key >=48 && key <= 57 ) || ( key >=96 && key <= 105 ) || key==8)
    {
       return true;
    }else{
       alert("숫자만 입력해주세요.");
       return false;
    }
}