Home » Php » syntax – What are the PHP operators "?" and ":" called and what do they do?


Posted by: admin April 23, 2020 Leave a comment


What are the ? and : operators in PHP?

For example:

How to&Answers:

This is the conditional operator.

$x ? $y : $z

means “if $x is true, then use $y; otherwise use $z“.

It also has a short form.

$x ?: $z

means “if $x is true, then use $x; otherwise use $z“.

People will tell you that ?: is “the ternary operator”. This is wrong. ?: is a ternary operator, which means that it has three operands. People wind up thinking its name is “the ternary operator” because it’s often the only ternary operator a given language has.



What is a ternary operator?

A ternary ? : is shorthand for if and else. That’s basically it. See “Ternary Operators” half way down this page for more of an official explanation.

As of PHP 5.3:


As of PHP 7.0

PHP 7 has new Null Coalesce Operator. This is the same as a ternary but is also called an “isset ternary“. This also allows a set of chained ternaries that remove the need for isset() checks.

In PHP 5, if you wanted to use a ternary with a potentially non-existent variable then you would have to perform an isset() at the beginning of the ternary statement:

$result = isset($nonExistentVariable) ? $nonExistentVariable : ‘default’;

In PHP 7, you can now do this instead:

$result = $nonExistentVariable ?? ‘default’;

The Null Coalesce Operator does not work with an empty string, however, so bear that in mind. The great thing about this is you can also chain the operators for multiple checks for multiple variables, providing a sort of backup depending on whether or not each variable in the chain exists:

$user = $userImpersonatingAnotherUser ?? $loggedInUser ?? “Guest”;

In PHP, with systems where a user can login, it is not uncommon for an administrator to be able to impersonate another user for testing purposes. With the above example, if the user is not impersonating another user, and also a logged in user does not exist, then the user will be a guest user instead. Read on more if you don’t understand this yet to see what ternaries are and how they are used, and then come back to this bit to see how the new PHP

How are ternaries used?

Here’s how a normal if statement looks:

    $var = 'exists';
    $var = 'error';

Let’s shorten that down into a ternary.

                 ^            ^     ^    ^     |
                 |           then   |   else   |
                 |                  |          |
          if post isset         $var=this   $var=this


$isWinner = false;

// Outputs 'you lose'

// Same goes for return

Why do people use them?

I think ternaries are sexy. Some developers like to show off, but sometimes ternaries just look nice in your code, especially when combined with other features like PHP 5.4’s latest short echos.


    <?php } ?>

<!-- Outputs:

Going off-topic slightly, when you’re in a ‘view/template’ (if you’re seperating your concerns through the MVC paradigm), you want as little server-side logic in there as possible. So, using ternaries and other short-hand code is sometimes the best way forward. By “other short-hand code”, I mean:

if ($isWinner) :
    // Show something cool


How fast is the ternary operator?

People LIKE micro-optimisations. They just do. So for some, it’s important to know how much faster things like ternaries are when compared with normal if / else statements.

Reading this post, the differences are about 0.5ms. That’s a lot!

Oh wait, no it’s not. It’s only a lot if you’re doing thousands upon thousands of them in a row, repeatedly. Which you won’t be. So don’t worry about speed optimisation at all, it’s absolutely pointless here.

When not to use ternaries

Your code should be:

  • Easy to read
  • Easy to understand
  • Easy to modify



That was pointless for three reasons:

  • Ridiculously long ternary embedding
  • Could’ve just used a switch statement
  • It was orange in the first place


Ternaries really are simple and nothing to get too worked up about. Don’t consider any speed improvements, it really won’t make a difference. Use them when they are simple and look nice, and always make sure your code will be readable by others in the future. If that means no ternaries, then don’t use ternaries.



It’s basically a shorthand if statement, and the above code could also be rewritten as follows:

if ($request_type == 'SSL') {
else {






variable = condition ? expression1 : expression2;

It works as follows…

  1. Firstly, condition is evaluated.

For example:

x = (a>b) ? 5 : 9


Ternary Operator


x ? y : z



This is a short way of writing if sentences. It is also used in other languages like Java, JavaScript and others.

Your code,


can be written like this:

if ($request_type == 'SSL')
    $protocol = HTTPS_SERVER;
    $protocol = HTTP_SERVER;


That is a one line if statement:

condition ? true : false


if($request_type == 'SSL') HTTPS_SERVER;


That’s basically a fancy way of writing an ifelse statement. Some say it’s easier to read, some say not.

Ternary operator at Wikipedia



if($request_type == 'SSL')