What does this PHP syntax mean? (question marks)

Question

What does this line of PHP code mean? That is, the question mark bit followed by true, colon, false?

return(isset($_SESSION['id'])) ? true : false;

Answer 1

It's a ternary operator.

It's simply short-hand for:

if (isset($_SESSION['id']))
  return true;
else
  return false;

Answer 2

Same as:

if isset($_SESSION['id']) {
     return true;
} else {
     return false;
}

Answer 3

This syntax is for Ternary operators in PHP

It runs like (Condition to evalute) ?( Return result if condition is true) : (return result if condition is false)

in your case return(isset($_SESSION['id'])) ? true : false;

if $_SESSION['id'] is set it will return true and if session is not set it will return false.

? mark is equivalent for if statement while : is for else

It is short form of if else statement

link : http://davidwalsh.name/php-shorthand-if-else-ternary-operators

Answer 4

This is a ternary operator.short for

if(isset($_SESSION['id'])){ 
   return true;
 }else{ return false;}

However this is useless because isset() already returns true or false

Answer 5

? boolean-condition [action] : [action] is the ternary conditional operator and is short for:

if ([condition]) { [action] } else { [action] }