JSFiddle - React, Tailwind, and code Playground
by MD RAHMAN
HTML
<input type="text" id="username" onkeyup="getLength()">
<input type="submit" id="test">
JavaScript
function getLength() {
var summonerid = document.getElementById("username").value.length;
return summonerid;
}
function lengthCheck() {
var getLengthValue = getLength();
if(getLengthValue == 4) {
alert("come on");
} else {
alert("wai");
}
}
var button = document.getElementById("test");
button.addEventListener('click', lengthCheck, false);