JSFiddle - React, Tailwind, and code Playground

by zlojnaxa

HTML

<div class="input-wrap">Введите данные</div>

<input class="item" type="text" id="item1" placeholder="№1">
<input class="item" type="text" id="item2" placeholder="№2">
<input class="item" type="text" id="item3" placeholder="№3">
<input class="item" type="text" id="item4" placeholder="№4">

<button class="btn" disabled>Ввести данные</button>

JavaScript

dataCheck();
function dataCheck() {
	var item = document.querySelectorAll('.item'), btn = document.querySelectorAll('.btn')[0], str;
	[...item].map((e,i)=>{
		e.addEventListener('keyup',()=> {
			str = '', [...item].map((e,i)=> str += e.value );
			str !== '' ? btn.disabled = false : btn.disabled = true;
		});
	});
}