JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" />
<br/>
<button onclick="validate();">Test</button>

JavaScript

function validate() {
    var x = document.getElementsByTagName("input")[0].value;
var regex=[A-Za-z];
    if (x === null || x.trim() === "" || !x.match(regex)) {
        alert("At least 8 characters are required!");
        return false;
    } else {
        alert("All good!");
    }
}