what am I doing wrong?

So the answer is....

<?php

$numbers = array(1,5,8);

$sum = 0;

$sum = array_sum($numbers);

echo $sum;

?>

And here is why. The question says that the function array_sum will calculate the sum of an array. So what you want to do is get rid of the for loop because you have a function now to do that same thing... and as you see you set the sum = to the return of that function (array_sum()).

Notice how we use a different line for each operation. You are trying to do to much on 1 line and confusing syntax.

I see that you have confusing calling a function and writing a function.

When you call a function it is usually function_name($Some_Parameter); and If you want what that function is doing captured in a variable like this question is asking you put the variable name = the function call. Like above.

When declaring a function it is...

function_name($some_parameter) { DO STUFF IN HERE return someSortaReturnValue; }

Hope this helps