How TO - JS Validation For Empty Fields


Learn how to add form validation for empty input fields with JavaScript.


Form Validation For Empty Inputs


Step 1) Add HTML:

Example

<form name="myForm" action="/action_page.php" onsubmit="return validateForm()" method="post" required>
  Name: <input type="text" name="fname">
  <input type="submit" value="Submit">
</form>

Step 2) Add JavaScript:

If an input field (fname) is empty, this function alerts a message, and returns false, to prevent the form from being submitted:

Example

function validateForm() {
  var x = document.forms["myForm"]["fname"].value;
  if (x == "") {
    alert("Name must be filled out");
    return false;
  }
}
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