CODEWITHSUNDEEP
phpclassconstants
thelolcat
thelolcat

Reputation: 11545

Are there any benefits on using class constants instead of global constants?

Class constant

class Hello{    
  const SOME_SETTING = 5;

}

Normal constants

define('HELLO_SOME_SETTING', 5);

To access the class constant I have to call

Hello::SOME_SETTING

To access the normal constant

HELLO_SOME_SETTING

So far both are ok, but what happens if I want to update the value of some constants? I would have to browse .php files, track down each class and modify the constants.

But using normal constants I would just place all defines inside a single config file or something, where I can easily find them when I need to change something.

This is one disadvantage of class constants in my opinion. Are there any advantages?

Upvotes: 1

Views: 181

Answers (1)

Jon
Jon

Reputation: 437336

The main advantage is locality, which affords better organizational structure. If you have a class BufferedReader that uses a BUFFER_SIZE constant, it's much better for the constant to be defined alongside the code that uses it.

But using normal constants I would just place all defines inside a single config file or something, where I can easily find them when I need to change something.

That's IMHO the wrong way to use constants (although this practice is quite widespread). A constant is something that, as far as can be foreseen, will not change -- for example, the number of days in a week. What you are describing here is a configuration variable.

Upvotes: 7

Related Questions