How to call PHP function through JavaScript?

Question

I'm trying to call a PHP function from an external PHP file into a JavaScript script. My code is more complex, so I'm writing a sample code here.

This is my PHP code:

<code><?php
function add($a,$b){
  $c=$a $b;
  return $c;
}
function mult($a,$b){
  $c=$a*$b;
  return $c;
}

function divide($a,$b){
  $c=$a/$b;
  return $c;
}
?>
</code>

JS code:

<script>
  var phpadd= add(1,2); //call the php add function
  var phpmult= mult(1,2); //call the php mult function
  var phpdivide= divide(1,2); //call the php divide function
</script>

This is what I want to do.

My original PHP file did not contain these math functions, but the idea is the same.

If there is no suitable solution, can you please provide an alternative, but it should call the value from an external PHP file.

Answer 1

Try this

<script>
  var phpadd= <?php echo add(1,2);?> //call the php add function
  var phpmult= <?php echo mult(1,2);?> //call the php mult function
  var phpdivide= <?php echo divide(1,2);?> //call the php divide function
</script>

Answer 2

Yes, you can send an Ajax request with data to the server using request parameters, like this (very simple):

Please note that the following code uses jQuery.

jQuery.ajax({
    type: "POST",
    url: 'your_functions_address.php',
    dataType: 'json',
    data: {functionname: 'add', arguments: [1, 2]},

    success: function (obj, textstatus) {
                  if( !('error' in obj) ) {
                      yourVariable = obj.result;
                  }
                  else {
                      console.log(obj.error);
                  }
            }
});

Your _functions_address.php file should look like this:

<?php
    header('Content-Type: application/json');

    $aResult = array();

    if( !isset($_POST['functionname']) ) { $aResult['error'] = 'No function name!'; }

    if( !isset($_POST['arguments']) ) { $aResult['error'] = 'No function arguments!'; }

    if( !isset($aResult['error']) ) {

        switch($_POST['functionname']) {
            case 'add':
               if( !is_array($_POST['arguments']) || (count($_POST['arguments']) < 2) ) {
                   $aResult['error'] = 'Error in arguments!';
               }
               else {
                   $aResult['result'] = add(floatval($_POST['arguments'][0]), floatval($_POST['arguments'][1]));
               }
               break;

            default:
               $aResult['error'] = 'Not found function '.$_POST['functionname'].'!';
               break;
        }

    }

    echo json_encode($aResult);

?>