[RESOLVED] array and fuction question

Zach85

I'm reading a "Dummies" book on PHP and MySQL. I'm learning about "passing the right type of values" and came across this script:

<?php

function add_numbers($numbers)
{
	if(is_array($numbers))
	{
		for($i=0;$i <sizeof($numbers);$i++)
		{
			@$sum = $sum + $numbers($i);
		}
		echo $sum;
	}
	else
	{
		echo "value passed is not an array";
		return;
	}
}

$arrayofnumbers = array(100,200);
add_numbers($arrayofnumbers);

?>

According to the book it says that it should display 300, but when I typed this script in word-for-word into AceHTML (program I'm using) and viewed it in both IE and Firefox, it just displays a blank page, and in the source of the page it just says

<html>
</html>

am I doing something wrong? I've checked each letters, numbers and special characters, and it seems to be exactly as it is written in the book. Any help would be appreciated!

bradgrafelman

If the book honestly uses the @ error suppressor so freely like that, then I would highly suggest you get a better book.

Remove the @ symbol from the line inside the for() loop and you'll see that PHP is trying to report a fatal error on that line. The error comes from the fact that array indexes are accessed using square brackets ( [] ), not parenthesis.

dagon

typo on your part or the book, however this

@$sum = $sum + $numbers($i);

should be

@$sum = $sum + $numbers[$i];

note the () and []

as a teaching exercises this may work, but i can achieve the same results a lot easier:

echo  array_sum($arrayofnumbers);

Zach85

yes, the books does have [] and not ()... that was my typo.

It's an "outdated" Dummies book that I got at a discount store so instead of paying then MSRP of $50 I got the book for $8. I'm using this to get me started with php, and eventually I'll go with a better, more advanced book. For my first ultimate project I want to build a very small text-based RPG game using php, and if it gets some notice from people I will build it to be bigger and include graphics. In the meantime, I'll stick with this book to learn.

Thanks again for the help and suggestions. I can now move along the book without confusions!

Zach85

dagon;10930531 wrote:
as a teaching exercises this may work, but i can achieve the same results a lot easier:
echo  array_sum($arrayofnumbers);

That's probably later in the book, but thanks for the heads up!

dagon

i've never read a php book, you can learn it all using the internet alone, but i know some people prefer books., just be careful its up to date as things change very fast in the computer world.

Chuncho

Just a suggestion...

You have this...

for($i=0;$i <sizeof($numbers);$i++)

It's much better do this...

$sizeof = sizeof($numbers);
for($i=0;$i < $sizeof;$i++)

It will be helpful in your projects.

See you

Zach85

Chuncho;10930581 wrote:
Just a suggestion...

You have this...
for($i=0;$i <sizeof($numbers);$i++) 
It's much better do this...
$sizeof = sizeof($numbers);
for($i=0;$i < $sizeof;$i++) 
It will be helpful in your projects.

See you

Thanks. I'm just following this book now, but with more experience and my logical capable mind I probably could have figured that out later on. Thanks again!