What does this syntax ( page = $page ? $page : ‘default’ ) in PHP mean?

7 comments

1. That’s the ternary operator:

   That line translates to

   if ($page)
       $page = $page;
   else
       $page = 'default';
   

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2. It’s an example of the conditional operator in PHP.

   It’s the shorthand version of:

   if (something is true ) {
       Do this
   }
   else {
       Do that
   }
   

   See Using If/Else Ternary Operators
   http://php.net/manual/en/language.operators.comparison.php.

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3. It’s a ternary operation which is not PHP or WordPress specific, it exists in most langauges.

   (condition) ? true_case : false_case 
   

   So in this case the value of $page will be “default”, when $page is something similar to false — otherwise it will remain unchanged.

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4. It means that if $page does not have a value (or it is zero), set it to ‘default’.

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5. It means if the $page variable is not empty then assign the $page variable on the last line that variable or set it to ‘default’ page name.

   It is called conditional operator

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6. More verbose syntax of the last line is:

   if ($page)
   {
       $page = $page;
   }
   else
   {
       $page = 'default';
   }
   

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7. That’s the so-called conditional operator. It functions like an if-else statement,
   so

   $page = $page ? $page : 'default';
   

   does the same as

   if($page)
   {
       $page = $page;
   }
   else
   {
       $page = 'default';
   }
   

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