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PHP Build a Simple PHP Application Working With Functions Introducing User-Defined Functions

why?

In the main code, outside of the function, use the new mimic_array_sum() function you just wrote. Store the return value in a variable called $sum, and then display that sum to the screen.

Bummer! It looks like you have not created a variable named $sum in your main code, outside of the function. Please create it and store the return value from the mimic_array_sum function call in it.

palindromic_primes.php
<?php 

function mimic_array_sum($array) {


  foreach($array as $number) {
     $sum += $number;
    }

  return $sum; //return the value of $sum

  }
$sum = mimic_array_sum($sum);
echo $sum;


$palindromic_primes = array(11, 757, 16361);

?>

3 Answers

Chris Adamson
Chris Adamson
132,142 Points

You were pretty close, you need to pass an array, not the variable sum into the mimic_array_sum function:

<?php 

$sum = 0;

function mimic_array_sum($array) {

  foreach($array as $number) {
     $sum += $number;
    }

  return $sum; //return the value of $sum

  }

$sum = mimic_array_sum(array(11, 757, 16361));
echo $sum;

$palindromic_primes = array(11, 757, 16361);

?>
Kevin Korte
Kevin Korte
28,111 Points

You're passing to your new mimic_array_function and argument of $sum, however that variable does not exist anywhere in a scope that your function can access it. So essentially you're passing your function the value of nil. Instead of passing it $sum you need to pass it something it can add, like that $palindromic_primes variable which we know has an array of numbers.

thank you!