How to check if form fields contain a value with PHP

I had earlier published a post where you can easily check your form fields server side with PHP and alert the user that some of the fields are empty here.

Well, good news is that the script works just fine but here are some things I noticed on the previous script.

- If you shortened the field name, it gets outputed just like that.

Eg; lname is required, fname is required, num is required instead of last name is required, first name is required, phone number is required.

- There's no return value included, so you have to include the script at the start of your ($_POST) block for it to work just fine.

NOTE

I will be tagging the releases to this PHP script and future updates will be available right on GitHub.

UPDATE 1.2

I have used a function and have included two (2) arguments to the function. You can call the function like this :

//syntax
checkFormFields(fields_array, return);

//call the function

$fields = [
"fname" => "First Name",
"lname" => "Last Name",
"email" => "Email Address"
 ];

checkFormFields($fields, true)

fields_array This will be the array that will hold your form fields that are to be filled up by users.

return This is a Boolean that will specify if the function should return a value .

if the value returned is 1, it means that some fields are missing a value. if the value returned is 0, it means that no fields are missing a value.

So you can check if the value returned by the function is 1 or 0 ;

if (checkFormFields($fields, true) == 1) {
    echo "one or more fields are empty";
} else {
    echo "No field is empty";
}

The return argument must be set to true if you want to use the return value.

FULL SCRIPT

Here's the full script below.

function checkFormFields($fields, $return) {

    $requiredFields = [];  //init required fields var
    $emptyFields = array();  //init empty fields var


  foreach ($fields as $field=>$fieldTag) //loop through the array to find the fields and field tags associated
{

    array_push($requiredFields, $field);  //push required field to the array

} //end of foreach loop

foreach($requiredFields as $requireField) {

     $currentField = $requireField; //store current field
     $currentFieldTag = $fields[$currentField]; //store current field tag

  if (!($_POST[$currentField]))
{
      array_push ($emptyFields, $currentFieldTag); //push the tag name to the empty field

} //end of if field is empty

} //end of check if field has a value

 /***
     * 
     * IF FIELD IS EMPTY BLOCK
     * 
 ***/

if (isset($emptyFields) && count($emptyFields) > 0) //check if there's an empty field in the variable
{ // then loop through

  foreach ($emptyFields as $emptyField)   {

/***
     * 
     *  CUSTOM USER ALERT ACTION GOES HERE 
     *
    ** */

    echo '
       <script>
        document.addEventListener(\'DOMContentLoaded\', function(){
       alert(\''.$emptyField.' is required!\');
        });
       </script>'; //ALERT THE USER 

} //END OF empty fields loop

} //end of check if there's an empty field

//if return is set to true
if($return == true) {
  if (isset($emptyFields) && count($emptyFields) > 0) {
        return(1);
}   else {
        return (0);
} 
}
} //end of function

Before you use it, make sure you have created an empty php page and have added some form fields like;

 <html>
     <form method="post">
         <input name="fname"> <br>
         <input name="lname"> <br>
         <input name="email"> <br>
         <button type="submit">Submit</button>
     </form>
 </html>

Then for server side processing;

if ($_POST){
$fields = [
    "fname" => "First Name",
    "lname" => "Last Name",
    "email" => "Email"
];

//call the function

if (checkFormFields($fields, false) == 1) {
    echo "one or more fields are empty";
} else {
    echo "No field is empty";
}
}