## Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

### Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial###### Tony McCabe

8,445 Points# Introduction User-Defined Function 3of 3

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.<?php

function mimic_array_sum($sum) { $sum = 0;

```
foreach($array as $element) {
$sum = $sum + $element;
}
return $sum;
```

}

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

?>

## 11 Answers

###### Randy Hoyt

Treehouse Guest TeacherWell, I do have all the answers here in my top-secret briefcase. :-)

```
____
.---[[__]]----.
;-------------.|
| ||
| ||
| ||
|_____________|/
```

###### Tony McCabe

8,445 PointsBummer!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. where do you place the variable?

###### Randy Hoyt

Treehouse Guest TeacherYour function code looks right. Now you need to create a variable *outside* of the function, like this:

```
function mimic_array_sum($sum) {
$sum = 0;
foreach($array as $element) {
$sum = $sum + $element;
}
return $sum;
}
$palindromic_primes = array(11, 757, 16361);
$sum = ____;
```

###### Tony McCabe

8,445 Points$sum = 17118; $sum = 0; $sum = return; Which one or do I need to go back to math class

###### Randy Hoyt

Treehouse Guest TeacherThe instructions ask you to do this:

Please create it and store the return value from the mimic_array_sum function call in it.

That means do this:

```
$sum = mimic_array_sum($palindromic_primes);
```

In earlier step, we wrote the `mimic_array_sum`

function that receives an array of numbers and adds up all its elements. In this step, we need to *call* that function. We pass in an array of numbers (`$palindromic_primes`

), and the function returns the sum of them. We then load that return value into a variable named `$sum`

.

Does that help?

###### Tony McCabe

8,445 Points<?php

function mimic_array_sum($array) {
$sum $sum;

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

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

$sum = mimic_array_sum($palindromic_primes); ?> "Still say's bummer!

###### Randy Hoyt

Treehouse Guest Teacher"Bummer" means you have invalid PHP code. You changed a line from what you sent me earlier. You now have this ...

```
<?php
function mimic_array_sum($array) {
$sum $sum;
```

... but you used to have this:

```
<?php
function mimic_array_sum($array) {
$sum = 0;
```

It was correct before, and you'll need to change it back.

###### Tony McCabe

8,445 PointsIt looks like you are not displaying anything to the screen. Be sure to use an echo command.

function mimic_array_sum($array) { $sum = 0; I tried: echo sum = 0 echo 0;

###### Randy Hoyt

Treehouse Guest TeacherTry this:

```
echo $sum;
```

###### Randy Hoyt

Treehouse Guest TeacherOh, but not inside the function. You need to do that at the end of your code.

```
$sum = mimic_array_sum($palindromic_primes);
echo $sum;
```

###### Tony McCabe

8,445 Pointsperfect your a genius!!