JSFiddle - React, Tailwind, and code Playground
HTML
<input type="text" class="inputCheck">
<input type="text" class="inputCheck">
JavaScript
var elements = document.querySelectorAll(".inputCheck");
for(var index=0;index< elements.length; ++index) {
elements[index].addEventListener("keypress", function(event) {
var keychar = String.fromCharCode(event.keyCode);
var testStr = this.value + keychar;
if(! /^\d+\.?\d?$/.test(testStr))
event.preventDefault();
})
}