Using Ternary Operator without the Else statement PHP

Question

Can you use the Ternary Operator in PHP without the closing 'else' statement? I've tried it and it's returning errors. Google search isn't yielding anything, so I think the answer is probably no. I just wanted to double check here. For instance:

if ( isset($testing) {
  $new_variable = $testing;
}

Will only set $new_variable if $testing exists. Now I can do

$new_variable = (isset($testing) ? $testing : "");

but that returns an empty variable for $new_variable if $testing isn't set. I don't want an empty variable if it's not set, I want the $new_variable to not be created.

I tried

$new_variable = (isset($testing) ? $testing);

and it returned errors. I also tried

$new_variable = (isset($testing) ? $testing : );

and it also returned errors. Is there a way to use the Ternary Operator without the attached else statement, or am I stuck writing it out longhand?

EDIT: Following Rizier123's advice, I tried setting the 'else' part of the equation to NULL, but it still ends up appending a key to an array. The value isn't there, but the key is, which messes up my plans. Please allow me to explain further.

The code is going to take a bunch of $_POST variables from a form and use them for parameters in a stdClass which is then used for API method calls. Some of form variables will not exist, as they all get applied to the same variable for the API call, but the user can only select one. As an example, maybe you can select 3 items, whichever item you select gets passed to the stdClass and the other 2 don't exist.

I tried this:

$yes_this_test = "IDK";
$setforsure = "for sure";
$list = new stdClass;
$list->DefinitelySet = $setforsure;
$list->MaybeSet = (isset($yes_this_test) ? $yes_this_test : NULL);
$list->MaybeSet = (isset($testing) ? $testing : NULL);
print_r($list);

But obviously MaybeSet gets set to NULL because (isset($testing) comes after (isset($yes_this_test) and it returns

stdClass Object ( [DefinitelySet] => for sure [MaybeSet] => )

I won't know what order the $_POST variables are coming in, so I can't really structure it in such a way to make sure the list gets processed in the correct order.

Now I know I can do something like

if ( isset($yes_this_test ) {
  $list->MaybeSet = $yes_this_test;
}
elseif ( isset($testing) ) {
  $list->MaybeSet = $testing;
}

But I was hoping there was a shorthand for this type of logic, as I have to write dozens of these. Is there an operator similar to the Ternary Operator used for if/elseif statements?

Another option is to use the if statement without the curly braces. It could be on one line similar to a ternary as well. if(isset($testing)) $new_variable = $testing;. IMO I don't like if without curly braces but just saying it is possible. IMO it would be better to just set it to NULL like Rizier is suggesting because isset will return false if the value is NULL. isset($nullVar) will return false. — Jonathan Kuhn
– Jonathan Kuhn, Commented Mar 31, 2015 at 17:35
Possible duplicate of Ternary Operators. Possible for a one sided action? — Ani Menon
– Ani Menon, Commented May 27, 2016 at 2:54

Kenny · Accepted Answer · 2020-01-29 19:46:12Z

68

Since PHP 5.3 you can do this:

!isset($testing) ?: $new_variable = $testing;

As you can see, it only uses the part if the condition is false, so you have to negate the isset expression.

UPDATE

Since PHP 7.0 you can do this:

$new_variable = $testing ?? null;

As you can see, it returns its first operand if it exists and is not NULL; otherwise it returns its second operand.

UPDATE

Since PHP 7.4 you can do this:

$new_variable ??= $testing;

It leaves $new_variable alone if it isset and assigns $testing to it otherwise.

edited Jan 29, 2020 at 19:46

Kenny

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answered Apr 29, 2016 at 8:27

Daan

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4 Comments

ahnbizcad Over a year ago

The fact that PHP allows empty value in the "truthy" slot but not the "falsey" slot is ridiculous. What goes on in the PHP language maintainers' minds? !isset($testing) ? : $new_variable = $testing; but not !isset($testing) ? $new_variable = $testing;

patrickj Over a year ago

@ahnbizcad It's not an actual empty value, just syntactic sugar to use the first operand. I agree it would be nice to have an equivalent that uses null if the third operand is omitted, but that would probably require a new operator.

ahnbizcad Over a year ago

Maybe the syntactic sugar sucks and is actually syntactic aspartame.

achasinh Over a year ago

Love the "null coalescing assignment operator" (??=) addition in PHP 7.4

Rizier123 · Accepted Answer · 2015-03-31 17:27:42Z

14

Just set it to NULL like this:

$new_variable = (isset($testing) ? $testing : NULL);

The you variable would return false with a isset() check.

You can read more about NULL in the manual.

And a quote from there:

The special NULL value represents a variable with no value. NULL is the only possible value of type null.

A variable is considered to be null if:

it has been assigned the constant NULL.
it has not been set to any value yet.
it has been unset().

answered Mar 31, 2015 at 17:27

Rizier123

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12 Comments

Longblog Over a year ago

Perfect! Thank you. I always assumed NULL was pretty much the same as empty. I guess I should assume less and read more. ;)

Longblog Over a year ago

Bah, actually after testing it just now, it still appends the variable to a list, just as an empty variable. I don't know if this will work because I'm going to have to use it for an array of parameters using $_POST variables as parameters. I don't know in what order the $_POST variables will come through, so I might end up with a NULL parameter, even though one of the $_POST variables is set. I'll explain further above.

Rizier123 Over a year ago

@Longblog yeah just edit your question and put it in there, so that I see what you mean

Longblog Over a year ago

OK I have added additional details as well as an example. Thanks for your help.

Rizier123 Over a year ago

@Longblog Just add this at the end: $list = (object) array_filter((array)$list, function ($v){ return !is_null($v); }); And this will remove all values which have the value NULL. The problem is that this is in a class, so it's just like a defined property with no value

|

groenhen · Accepted Answer · 2020-10-21 10:58:22Z

2

Since PHP 7.0 you can do the following, without getting an ErrorException "Trying to get property 'roomNumber' of non-object":

$house = new House();
$nr = $house->tenthFloor->roomNumbers ?? 0

Assuming the property "tenthFloor" does not exist in the Class "House", the code above will not throw an Error. Whereas the code below will throw an ErrorException:

$nr = $house->tenthFloor->roomNumbers ? $house->tenthFloor->roomNumbers : 0

edited Oct 21, 2020 at 10:58

groenhen

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answered Oct 21, 2020 at 10:17

cosmorunner

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Comments

Marvin Fischer · Accepted Answer · 2018-07-27 13:47:57Z

1

You can also do this (short form):

isset($testing) ? $new_variable = $testing : NULL;

edited Jul 27, 2018 at 13:47

Marvin Fischer

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answered Jul 27, 2018 at 12:42

Arnaud Anato

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Comments

Pawan Vikasitha · Accepted Answer · 2022-03-09 16:25:17Z

1

JUST USE NULL TO SKIP STATEMENTS WHEN IT WRITTEN IN SHORTHAND

$a == $b? $a = 20 : NULL;

answered Mar 9, 2022 at 16:25

Pawan Vikasitha

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1 Comment

Eric Aya Over a year ago

Hello, please read Why is it considered inappropriate and unprofessional to type in all capital letters?. Thank you.

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