PHP ternary operator object assignment

Question

I have an object:

$info = [
    'last_name' => $this->askForLastName(),
];

I am trying to read an environment variable in the form of env('ADMIN_LAST_NAME', null) and trying to use the ternary operator so that it should only call the function if the env variable does not exist.

For instance:

$info = [
    'last_name' => env('ADMIN_LAST_NAME', null)? env('ADMIN_LAST_NAME', null) : $this->askForLastName(),
];

Is this the correct way?

Answer 1

It might be better to use the ternary operator shortcut .

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.

This way the env() function will be called just once (instead of twice):

$info = [
    'last_name' => env('ADMIN_LAST_NAME', null) ?: $this->askForLastName(),
];

It will work fine unless '' , null or false are valid admin last names.

Answer 2

That code should work, but it can be improved.

For one, since there is no alternative case for the true clause, you can use the shorthand ternary operator.

['last_name' => env('ADMIN_LAST_NAME', NULL) ?: $this->askForLastName()'] ;

Furthermore, while a null value will return false for an if clause, it's not very accurate or specific. If you want explicitly checking for null values, then use is_null . If you want null or false, use empty . In such a case, you will not be able to use the shorthand, as both the true / false clause must return a separate entity.

['last_name' => is_null(env('ADMIN_LAST_NAME', NULL)) ? $this->askForLastName() : env('ADMIN_LAST_NAME', NULL)]

You can take it a step further by getting rid of the multiple calls to env.

['last_name' => is_null(($adminLastName = env('ADMIN_LAST_NAME', NULL))) ? $this->askForLastName() : $adminLastName] ['last_name' => is_null(($adminLastName = env('ADMIN_LAST_NAME', NULL))) ? $this->askForLastName() : $adminLastName] .

It is a matter of code style and preference. Just keep it consistent throughout your codebase.