[SOLVED] ? and :

[sanchez77]

What does the ? and : mean in this statement.

 

Can someone break it down for like a small child, hold my hand, so i better understand please?

 

thanks

 

$color = strtotime(sprintf('%s/%s/%s', $m, $d, $y) > time()) ? '#00F' : '#F00';

[steveangelis]

Google

 

http://answers.yahoo.com/question/index?qid=20080202121355AAAMSl9

[waynew]

$result = (conditional statement) ? (result if true) : (result if false);

[sanchez77]

thanks, i get it now, cheers

[Daniel0]

It'll not work as intended though. Match up the parentheses and see why for yourself

[sanchez77]

what won't work, the principal or the code above?

[Daniel0]

Take a close look at this statement:

strtotime(sprintf('%s/%s/%s', $m, $d, $y) > time())

 

Evaluating from the inside and out we've got:

A = sprintf('%s/%s/%s', $m, $d, $y) - presumably, this is the some date in the format m/d/y. This is a string.

B = time() - this is the current UNIX timestamp and an integer.

 

So we are evaluating A > B. A will get cast to an integer because we are doing a numeric comparison. The way PHP handles this is by chopping off from the first non-numeric character. So essentially we are checking if the given month is larger than the current UNIX timestamp. This will never be the case, so the operation will return false (a boolean value).

 

Now, a boolean value is an invalid argument to strtotime(), and the way it handles this is by returning false. This means the ternary statement will always return the "false" component, i.e. "#F00" in this case.

 

 

You can of course fix this by fixing the parentheses:

strtotime(sprintf('%s/%s/%s', $m, $d, $y)) > time()

 

I'll let you work out the logic in that statement yourself

[sanchez77]

wow, I understand now, I appreciate you taking the time out to explain it to me. Thanks Again.