JAVASCRIPT

check if input has value javascript

var myInput = document.getElementById("customx");
if (myInput && myInput.value) {
  alert("My input has a value!");
}

how to check if input field has value

function check(){
  var checkInput = document.getElementById("inputName");
  if (checkInput.value) {
    checkInput.classList.remove("is-invalid");
  } else {
    checkInput.classList.add("is-invalid");
  }
}