set variable and compare in one command

[NotionCommotion]

I typically only use the first two solutions.  Is there anything wrong with the third?  Is there any more streamlined way to do it?

function f1($x){return $x*1;}
function f2($x){return $x*1;}

$x=2;$y=1;

if(f1($x)>f2($y)){echo(f2($y)."\n");}

// or

$f2_y=f2($y);
if(f1($x)>$f2_y){echo($f2_y."\n");}

// or

if(f1($x)>$f2_y=f2($y)){echo($f2_y."\n");}

[phpaddiction]

You could do it this way:

echo ( f1($x) > ($f2_y = f2($y)) ? $f2_y ."\n" : "";

That should work. I put the $f2_y inside brackets to have that executed first and assign f2($x) to $f2_y, then it should run the comparison and echo on true.

[phpaddiction]

Sorry a syntax problem on my first post

echo ( f1($x) > ($f2_y = f2($y))) ? $f2_y ."\n" : "";

This is correct

[NotionCommotion]

Thanks phpaddiction, and welcome to php freaks.

 

Do you know whether the parenthesis around setting $f2_y are absolutely required.  I looked at http://php.net/manual/en/language.operators.precedence.php, and wasn't sure whether = had higher precedence than >.  Regardless, I feel they make the code more readable.

[Barand]

 

 

Do you know whether the parenthesis around setting $f2_y are absolutely required.

 

You could always try it and see.

[NotionCommotion]

You could always try it and see.

 

I had done so before starting this post.  As far as I could tell, the equal sign has higher precedence than the > sign, and the parenthesis are not required.  Just couldn't find this documented anywhere.

[kicken]

I had done so before starting this post.  As far as I could tell, the equal sign has higher precedence than the > sign, and the parenthesis are not required.  Just couldn't find this documented anywhere.

Actually it has lower precedence.. Since the = comes after the > in the example, it works without the extra parenthesis.

 

This on the other hand: if($f1_x=f1($x) > f2($y)){ would be interpreted as $f1_x = (f1($x) > f2($y)) and $f1_x would be a boolean true/false not the return value of the function.

[NotionCommotion]

Thanks Kicken,

 

I am sure this is a little tiny detail which could cause a not so little headache.