string concatenation with constants

Question

I have only PHP 5.4 available at my current hoster and I always get errors with class constants in my code. Apparently, it's not allowed to define array constants. I changed the constant to a static variable to make it work. Now I get this syntax error:

    syntax error, unexpected '.', expecting ']'

I try to define strings that consist of concatenated constants.

public static $arr = [KEY_ONE => "string " . MyClass::CONSTANT . " string"]

is this possible or do all constants have to be static variables now?

Maybe a question of operator preference, did you try putting parentheses around the concatenation? Like in `[KEY_ONE => ("string " . MyClass::CONSTANT . " string")]`. — syck, Jun 23 '16 at 10:17

score 3 · Answer 1 · answered Jun 23 '16 at 10:22

3

In the variable declaration you cannot do operations. Neither concatenation nor math operations.

You can do it in construct method;

public static $arr = [];

public function __construct(){
  self::$arr = [KEY_ONE => "string " . MyClass::CONSTANT . " string"];
}

answered Jun 23 '16 at 10:22

David Rojo

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Or some sort of an `init()` method if you don't want to instantiate an object. – jeroen Jun 23 '16 at 10:25
This limitation of PHP 5.4 is informed here: https://www.php.net/manual/en/language.oop5.properties.php (see Example #1 property declarations). The possibility of doing concatenations, in class member variables, was introduced as of PHP 5.6. – aldemarcalazans Jul 31 '20 at 17:06

score 0 · Answer 2 · answered Jun 23 '16 at 10:17

0

if you are making array try like this:

public static $arr = array("KEY_ONE" => "string " . MyClass::CONSTANT . " string");

answered Jun 23 '16 at 10:17

Suresh Kamrushi

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string concatenation with constants

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