Syntax Problems of if Statement (php) - php

Question

I need a little help with an if statement in php. I'm trying to set a variable called offset according to a page that I am loading in WordPress. Here's the variable:
$offset = ($paged * 6);
What it does is it loads the first page, which is:
http://example.com/blog
and $offset is thus set to 0 because $paged is referring to the appending number on the URL. The second page, for example is:
http://example.com/blog/2/
which makes $offset set to 12. The problem is, I need the second page to define $offset as 6, the third page to define $offset as 12, etc. I tried using:
$offset = ($paged * 6 - 6)
which works except on the first page. On the first page it defines $offset as -6. SO, I wanted to create an if statement that says if $paged is equal to 0 then $offset is equal to 0, else $offset is equal to ($paged * 6 - 6).
I struggle with syntax, even though I understand what needs to be done here. Any help would be greatly appreciated. Thanks!

Answer 1

Because this is two different cases which cannot be easily integrated into a single formula, use an if statement:
if ($paged == 0)
$offset = 0;
else
$offset = ($paged - 1) * 6;
You can write this shorter using the ternary operator, but I think the above if statement is more readable:
$offset = ($paged == 0) ? 0 : ($paged - 1) * 6;

Answer 2

An alternative:
if($paged == 0) $paged = 1;
$offset = ($paged - 1) * 6;
or
$offset = ($paged) ? ($paged - 1) * 6 : 0;

Answer 3

you can use the following one line code
$offset = max(($paged - 1) * 6, 0);

Answer 4

You could use: $offset = max(0, $paged * 6 -6);. Which takes the maximum of 0 and the other value. If the other value is negative, then 0 will be the result.
Now, to use an if statement, this is how you would do it:
$offset = $paged * 6 - 6;
if ($offset < 0) {
$offset = 0;
}
Or:
if ($paged == 0) {
$offset = 0;
} else {
$offset = $paged * 6 - 6;
}
And you might want to use a ternary operator for this simple case:
$offset = ($paged == 0)? 0: ($paged * 6 - 6);
(which does the exact same thing as the above)
Note: You could replace 6*a-6 = 6*(a-1), but it's of no importance in the code, just readability...