PHP Shorthand If/Else Using Ternary Operators (?:)

Discussion

1. Joseph R. B. Taylor

   Nice job clarifying this! I keep forgetting the exact syntax for some reason…
2. Eddie Monge

   Your second echo example in the more examples is missing the first ‘e’ in the code.
3. Mikkel Lund

   Nice article. I use this all the time. Often if/else statements get way too complicated. I love to shorten code and the (?:) operator helps a lot. It’s even a lot better when you can shorten it more than a (?:) can do: Yesterday I saw this excample in a high-end PHP OOP book:

   if ($condition){
   return true;
   }
   else {
   return false
   }

   It’s a lot easier to just use:

   return condition;
• Johan H

  Mind you, the if-statement you supplied checks if $condition is NOT false, everything else will pass, which might not always be ideal.
• Bartosz Kalinowski

  You can always write:

  return !!$condition;

  To be sure that you return boolean.
4. Mike

   I’ve been looking for a good explanation of this, thank you.

   Now I’m off to scour my code for opportunities to practice.
5. jigish thakar

   ohh wow man, i really needed this
   thanks for sharing that with such nice explanation

   thanks again
6. A.Lepe

   @Richard:

   If you have some experience with Javascript I would say that it is similar to:

   var test = result || error; //Javascript
   $test = $result ?: $error; //PHP

   In which it would return “result” value if it is not empty [1]. Otherwise it will return “error” value.

   I hope I was clear.

   [1] : For empty values see: http://www.php.net/manual/en/function.empty.php
7. Oussama
8. Danny

   /* echo, inline */
   echo ‘Based on your score, you are a ‘,($score > 10 ? ‘genius’ : ‘nobody’); //harsh!

   I think you may a typo with the ‘,’ instead of a ‘.’
• MSinclair

  The comma is not a typo. Echo can take multiple strings as arguments. :)

  http://php.net/manual/en/function.echo.php
9. Stjepano

   These are nice shorthands, but be warned, it will make your code unreadable and less understandable.
• Kurimasta

  What Stjepano says

  If you code for longer, you start to let go of niftyness and look more towards readability.
  Using ternary operator wrong, indicates to me a lack of experience and/or youthful enthusiasm.

  If you use them:
  – never nest ternary operators
  – Store the result in a variable which is named after the result (Eg. $geniusStatusLabel = ($iq>120)?'genius':'below genius') and use the variable later.
  – Be consistent in preferred value (if applicable). Eg. the following looks ackward $var = !isset($_POST['var'])?null:$_POST['var']
10. GTershel

    Question

    What is wrong with this code, I keep receiving an error.
    Creating a sticky form and I am using a simple if (submit) then ($_POST['value'])

    
    Please enter your short description of the category (blurb):
            <textarea id="catblurb" name="catBlurb"  value="
            ">
            Please enter a small description about this category.
            
    

    I only need the if part of the if/else.

    Thanks for any help
• strykr

  For people that might see this when searching..

  $_POST['value'] should be $_POST['catBlurb']
11. David

    Hey Dave!
    I don’t use ternary very often, but is really nice in spots where things need to be tidy.

    I have a bit of a word of advice here on the use of ternary and collaboration. Dave addresses that in his points above, “Tips for Using Ternary Operators”.

    As a rule I use ternary only if the If/Else is a ‘single line of code’ <— Yes this is variable depending on screen size. Just don't go overboard when working collaboratively or if there is a chance some-one else will inherit the code.
12. Eight

    Great article.
    In the first example, I think it’s the same thing as doing :
    $var_is_greater_than_two = ($var > 2);
    Right ?
• Adrian W

  Technically yes, but the ternary operator lets you output whatever you want (i.e. a string “IT’S BIGGER!”, and not just true or false like in your example. This demonstrates how much more flexibility you get when using the ternary operator. :)
13. Kocio

    Excellent… would be. But parts of the page does not display under Opera/NetBSD. Please fix it. TIA
14. kirk bushell

    Good article, I’m glad some poeple cover this. One thing should be mentioned though – this should definitely not be used heavily. Embedded ternary operators, and nested ternary operators are a developer’s worst nightmare – it creates unnecessarily unreadable code that is difficult to maintain. Sometimes more code is better! :)
15. Imam Tauhid

    i’am looking for this thing , thx for your explanation bro.
16. Aksam Zarook

    Thank you for this explanation. I have a background in Java so coming to PHP I see many similar coding between the two. This is one of them. But I wanted to make sure its the same in both and found you via Google when searching.
17. Sky

    “Makes maintaining code quicker, easier” – I’d say that it’s quote contrary. It makes it more difficult and obscure, not easier (these statements are by far easier to accidentally skip or misunderstand while analysing the code than regular ifs).
18. Zik Uralov

    Thanks, David! You’re doing great job revealing PHP mysteries.
19. kil

    so, can i shorten this if else using ternary?

    if(1==$c){
            $a=10;
            $b=12;
    }
    elseif(2==$c){
            $a = 9;
            $b = 27;
    }
    elseif(3==$c){
            $a=11;
            $b=8;
    }else{
            $a = 0;
            $b = 0;
    }
    
• kokos

  You should use switch/case http://php.net/manual/en/control-structures.switch.php
20. ahmad

    wish we had a syntax to test something and assign it to l_value if the test was successfull
    like
    y = x > 4 ?; means y = x if x > 4

    or

    y = x > 4 ? : z; means y= x if x > 4 else y = z would be a shorthand for
    y= x > 4 ? x : z

    Note usually when we test a condition on a variable we want to assign the same value as above

    then we could have

    y = x > 4 ? w : z; means y = w if x > 4 else y = z
21. Axel

    Thanks.. This was just what I was looking for!
22. MT

    Thanks… That is what i am looking for, sample usage attracts me!
23. Jols (Bardz)

    Thanks bro, now I understand :)
24. Andreas Burg

    Since PHP 5.3, it is possible to leave out the middle part of the ternary operator. Expression expr1 ?: expr3 returns expr1 if expr1 evaluates to TRUE, and expr3 otherwise.
    http://www.php.net/manual/en/language.operators.comparison.php#language.operators.comparison.ternary

    You should show an example e.g.

    echo $username ?: ‘unknown’;
    // same as
    echo $username ? $username : ‘unknown’;
• John

  Thanks for clarifying this only works from PHP 5.3+, I was getting nuts trying to figure it out why it wasn’t working.
25. Martin

    Unlike (literally!) every other language with a similar operator, ?: is left associative. So this:

      $arg = 'T';
      $vehicle = ( ( $arg == 'B' ) ? 'bus' :
                   ( $arg == 'A' ) ? 'airplane' :
                   ( $arg == 'T' ) ? 'train' :
                   ( $arg == 'C' ) ? 'car' :
                   ( $arg == 'H' ) ? 'horse' :
                   'feet' );
      echo $vehicle;
    

    Will output: horse
• Dan

  $arg = 'T';
  echo $vehicle = (
      ( $arg == 'B') ? 'bus'      : 
      (($arg == 'A') ? 'airplane' :
      (($arg == 'T') ? 'train'    :
      (($arg == 'C')  ? 'car'     :
      (($arg == 'H')  ? 'horse'   :
      'feet'
  )))));
  

  Not all languages do things the same way. So you should never expect the same behavior in any of them. Though be pleasantly surprised is they are. For all other cases adapt your code accordingly.

       string vehicle;
       string arg = "T";
  
       vehicle = ( ( arg == "B" ) ? "bus" :
                 ( arg == "A" ) ? "airplane" :
                 ( arg == "T" ) ? "train" :
                 ( arg == "C" ) ? "car" :
                 ( arg == "H" ) ? "horse" :
                 "feet" );
  
  cout << vehicle;
  
  Can also be written as:
  
       string vehicle;
       string arg = "C";
  
       vehicle = ( 
                 ( arg == "B" ) ? "bus" :
                 (( arg == "A" ) ? "airplane" :
                 (( arg == "T" ) ? "train" :
                 (( arg == "C" ) ? "car" :
                 (( arg == "H" ) ? "horse" :
                 "feet" 
       )))));
  
  cout << vehicle;
  

  Which is also usable in PHP in the same way. And both output the same result. This way if you want your code to be decently portable between languages, if that's a concern. Write it in a way that works either for both or decently for both.
26. Yotam

    Wow! I did not know that you don’t have to put a value after the question mark i.e. that you can do this:

    var $myvar = 'Hello ' . $test ?: ' World';

    Can I also do this:

    var $myvar = 'Hello ' . $test ? ' World' :;

    Or will that throw an error?
27. Jeff Lowery

    The ternary operator IS NOT the same as if/else; a ternary operator assures that a variable is given an assignment.

    var xylophone;
    
    if (foo) {
       xylophone = 'bar';
    } else {
       xylaphone = 'snafu';    //oops! and can be hard to spot
    }
    

    compare that to:

    var xylophone = foo? 'bar' : 'snafu';      // a misspelling here is easier to spot
    
28. Dan

    I did want to add that in PHP ternary does not always make code shorter than a if/else. Given that you can code in similar if/else blocks to that of ternary. Many people are so hooked on the typical logic that if/else requires specifically if and else and brackets { }. Then when you do deeply nested ternary you then use ( ). Though with deeply nested if/else you can forgo the brackets, you can not with ternary. A deeply nested if/else simply understands the flow of logic without them. IE so many )))))))))); at the end of a deeply nested ternary. Which you can forgo in a deeply nested if/else, which the blow structure can also be a part of.

    $a=3;$b=2;
    
    if($a>$b||die('Not Greater'))echo'Is Greater';
    
    echo$a>$b?'Is Greater':die('Not Greater');
29. Andreas

    Don’t do stupid things with PHP. Make your code human readable. i.e.

    $arg = 'T';
    
    $vehicle = array(
      'B' => 'bus',
      'A' => 'airplane',
      'T' => 'train',
      'C' => 'car',
      'H' => 'horse'
    );
    
    echo $vehicles[$arg] ?: 'feet';
    
30. Thomas

    Thanks for introducing me to this concept. It makes the code a lot shorter and once you are used to it even easier to read. I use this quite often now for example in this context:

    $comments = $numComments>1 ? "Comments" : "Comment";
31. Justin

    $var_is_greater_than_two = ($var > 2 ? true : false); // returns true
    

    could actually be just:

    $var_is_greater_than_two = ($var > 2); // returns true
    

    and its much clearer…

    Just my two cents.
• Adrian W

  Technically yes, but the ternary operator lets you output whatever you want (i.e. a string “IT’S BIGGER!”, and not just true or false like in your example. This demonstrates how much more flexibility you get when using the ternary operator. :)
32. Salvatore Capolupo

    Very clean and nice, thanks :-)
33. Andreas

    I linked to it in my first post http://davidwalsh.name/php-shorthand-if-else-ternary-operators#comment-78632

    > The expression (expr1) ? (expr2) : (expr3) evaluates to expr2 if expr1 evaluates to TRUE, and expr3 if expr1 evaluates to FALSE.

    Since PHP 5.3, it is possible to leave out the middle part of the ternary operator. Expression expr1 ?: expr3 returns expr1 if expr1 evaluates to TRUE, and expr3 otherwise.
34. Crozoom

    The ternary operator shouldn’t differ in performance from a well-written equivalent if/else statement…
    The only potential benefit to ternary operators over plain if statements in my view is their ability to be used for initializations

    $val=($x>5)?true;false;
    
35. Yiannis

    You mention in your article a list of advantages but you fail to mention the disadvantages. Also, one would argue that some of the claimed advatages are questionable. For example it can make maintaining the code slower and harder instead of quicker and easier if the expression in the ternary operator is not completely basic.

    Some other disadvantages.
    – Code is more prone to cause a conflicts when merging changes from different developers.
    – It makes debugging more difficult since you can not place breakpoints on each of the sub expressions.
    – It can get very difficult to read
    – It can lead to long lines of code
36. Gildus

    Another disadvantage for the operators ternary is more slow than the operator traditional, or not?
37. Gildus

    For example:

    http://fabien.potencier.org/the-php-ternary-operator-fast-or-not.html
38. David

    What do you mean by “Job security”?
39. Appunni M

    return !!$condition
40. Sankalp

    Good One “Job Security”!
41. Virre

    For flexibility yes, for readability no. It looks like a mess at first glance if overused and I’m not a fan of it unless i need to use it.
42. Howard

    In php, does the

    value = expression-1 ? expression-2 : expression-3

    evaluate all of the expressions before assigning the expression-2 or the expression-2 result to the value based on the expression-1, without or without short-circuiting? If so, then care must be taken to ensure that both expression-2 and expression-3 (and, of coarse, expression-1) are valid, which makes using the ternary operator somewhat more complicated than it might at first seem, such as when handling optional parameters.