Se o valor da entrada for nulo, faça algo
if(document.getElementById("question").value.length == 0)
{
alert("empty")
}
Scary Salamander
if(document.getElementById("question").value.length == 0)
{
alert("empty")
}const checkEmpty = document.querySelector('#checkIt');
checkEmpty.addEventListener('input', function () {
if (checkEmpty.value && // if exist AND
checkEmpty.value.length > 0 && // if value have one charecter at least
checkEmpty.value.trim().length > 0 // if value is not just spaces
)
{ console.log('value is: '+checkEmpty.value);}
else {console.log('No value');
}
});const inputFeilds = document.querySelectorAll("input");
const validInputs = Array.from(inputFeilds).filter( input => input.value !== "");
console.log(validInputs) //[array with valid inputs]<input type="text" id="checkIt" required />