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PHP

Alex Forseth
Alex Forseth
8,017 Points
Posted by Alex Forseth
Alex Forseth
8,017 Points

Can someone walk me through this Quiz Question?

In the PHP Build A Basic Website course in the listing and sorting lessons there is a quiz titled "Working with Functions" - https://teamtreehouse.com/library/build-a-basic-php-website/listing-and-sorting-inventory-items/working-with-functions

For the life of me I cannot figure why the answer to the below is 6. Can someone walk me through it?

What does the following code display? 

$numbers = array(1,2,3,4);
$total = count($numbers);
$sum = 0;
$loop = 0;

foreach($numbers as $number) {
    $loop = $loop + 1;
    if ($loop < $total) {
        $sum = $sum + $number;
    }
}

echo $sum;

2 Answers

Ayoub Iken
Ayoub Iken
Courses Plus Student 337 Points

Hello there, Simply because when it comes to the last item which is 4, the if condition is false cause 4 isnt strict inferior to 4, so it doesnt add 4 to 6 ($sum). Take a pen and piece of paper, and walk through the foreach you ll get it better. Keep it up

Alex Forseth
Alex Forseth
8,017 Points
Alex Forseth
Alex Forseth
8,017 Points

I have never taken the time to break down a problem with a pencil and paper before but this worked. Its much easier to keep track of in your head this way. I always scoffed at it before. Thanks for the advice.

Ayoub Iken
Ayoub Iken
Courses Plus Student 337 Points

You're welcome, I'm glad I could be of help to you. it always helped when I didn't get a break from a loop or smthg. Keep up the great work. peace out

Jake Milburn
Jake Milburn
13,608 Points
Jake Milburn
Jake Milburn
13,608 Points

The foreach loop is going to take a value from the array, set it to $number and then run the code underneath. Every time the loop runs the $loop variable increases by one '$loop = $loop + 1' is the same as take the variable and add 1 to it. The final line is then very similar to what i have just explained for the loop. The $number variable is the number that has been pulled from the array, so in the first instance $number = 1. This number is then added to $sum which currently = 0.

So after running through once $loop = 1 and $sum = 1. We then go through the process again but with $number = 2. Loop increases by 1 and sum increases by 2 as we are adding $number to it which is now equal to 2.

So we now have loop=2 and $sum =3. We run the process again but with $number = 3. Loop increases to 3 and sum increases to 6 as we are adding 3 to its current value of 3.

The next time the loop tries to run, when is reaches the statement $loop < $total it stops and doesn't run any further leaving $sum = 6. The reason is stops is because $total = the count of $numbers (essentially how many number are there and the answer is 4). so 3>4 and the loop stops.

Hopefully this was helpful and keep going as some of the questions like this really confused me at the start as well.