$top += $i ? 12 : 0;
+12
A:
If $i is
- set
- and not
false - and not
null
increment $top by twelve; otherwise, by zero, implicitly turning $top (not $i) into a numeric variable if it isn't one already.
Pekka
2010-05-12 18:18:38
In addition, if `$i` is not set, it raises a warning.
R. Bemrose
2010-05-12 18:32:17
@R.B good point. To avoid the warning, `(isset($i) and ($i))` should be used instead of `$i`.
Pekka
2010-05-12 18:32:55
When $i is turned to a numeric variable, does it get the value 0?What is it about php that causes $i to be implicitly turned into a numeric var? And why is it implicitly changed to be numeric var, as opposed to a boolean (since the ternary operator might suggest a boolean codition)?
Eddified
2010-05-12 19:18:10
I still don't see why php expects $i to be an integer... Since the ternary operator is supposed to be similar to:`if ($a) { return $b; } else { return $c; }`Then why in the world does it "need" $i to be an int?
Eddified
2010-05-12 20:43:31
@Eddified arrrrrgh, now I see. `$i` is never expected to be an integer and will never be turned into one. *`$top`* will get turned into an integer through the `+0` operation. I put the wrong variable name into the text. Mea culpa, sorry sorry. Corrected and removed my comment.
Pekka
2010-05-12 20:50:32
Thanks, makes sense now!
Eddified
2010-05-12 21:35:21
+11
A:
If $i has a value set (not empty/null meaning condition resolves to true), then 12 is added to $top and 0 otherwise.
It is basically shorthand of:
if ($i)
{
$top += 12;
}
else
{
$top += 0;
}
Sarfraz
2010-05-12 18:18:52
@Sarfraz is right: If `$i` is not numeric before the operation, the `+0` would make an implicit conversion, so it's not 100% identical (even though in practice, it's probably not relevant as `$i` will probably be numeric). Good answer either way.
Pekka
2010-05-12 18:24:32
+2
A:
If $i is true (e.g., not zero or an empty string), 12 is added to $top. Otherwise, nothing is added to $top.
This is equivalent to
if($i)
$top = top + 12;
warrenm
2010-05-12 18:20:20
+1
A:
Increase value of $top by 12 if $i has true boolean value (ie. $i = 1, $i = true etc.) or by 0 if not.
http://www.php.net/manual/en/language.operators.assignment.php
Crozin
2010-05-12 18:20:53
A:
The $i ? 12 : 0 is a "shorthand" if statement. In this case, $i is evaluated as an expression. If the expression evaluates to true, then the value 12 is used as the r-value in the addition-assignment expression. If $i evaluates to false, then 0 is used as the r-value.
Mat
2010-05-12 19:07:58