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PHP Build a Simple PHP Application Working With Functions Introducing Functions

Fabrizio Rinaldi
Fabrizio Rinaldi
5,359 Points
Posted by Fabrizio Rinaldi
Fabrizio Rinaldi
5,359 Points

array_sum()

Task: The code below creates an array of numbers, loops through them one at a time, and sums their values. PHP actually has a native function that does this same thing: array_sum(). [The array_sum() function receives an array as its one and only argument, and it sends back the sum as the return value.] Modify the code below: remove the foreach loop and the working sum variable, replacing them with a call to the array_sum() function instead.

Exercise: <?php

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

$sum = 0; foreach($numbers as $number) { $sum = $sum + $number; }

echo $sum;

?>

I literally don't know where to start.

2 Answers

Ben Falk
Ben Falk
3,167 Points
Ben Falk
Ben Falk
3,167 Points

First off, you would want to remove this line, as the instructions say:

$sum = 0; foreach($numbers as $number) { $sum = $sum + $number; }

Then, check the documentation to see how you would use the array_sum() function. http://php.net/manual/en/function.array-sum.php

Since you have an array of numbers already created, you should be able to echo out the results of array_sum(), using the $numbers array. Hope that helps you get started?

Carrie Lones
Carrie Lones
4,370 Points
Carrie Lones
Carrie Lones
4,370 Points

So basically, the code that you're given, specifically the $sum variable and the foreach loop, work as a function in the sense that the $sum goes up when each $number is called, and you then echo out the $sum variable. What the code challenge is asking you to do is to replace that with the actual function array_sum().

Because the array_sum() function takes care of everything in the foreach loop, you don't need that at all, nor do you need the $sum variable which is solely used within that foreach loop. So you can get rid of the following: 

$sum = 0;
$foreach($numbers as $number) {$sum = $sum + $number; }
echo $sum;

and add in the array_sum() function instead, calling up the variable that holds the array, and then you echo that out.