Hướng dẫn const php
A constant is an identifier (name) for a simple value. As the name suggests, that value cannot change during the execution of the script (except for magic constants, which aren't actually constants). Constants are case-sensitive. By convention, constant identifiers are always uppercase. Note: Prior to PHP 8.0.0, constants
defined using the define() function may be case-insensitive. The name of a constant follows the same rules as any label in PHP. A valid constant name starts with a letter or underscore, followed by any number of letters, numbers, or underscores. As a regular expression, it would be expressed thusly: It is possible to define() constants with reserved or even invalid names, whose value can only be retrieved with the
constant() function. However, doing so is not recommended. Example #1 Valid and invalid constant names Note: For our purposes here, a letter is a-z, A-Z, and the ASCII characters from 128 through 255 (0x80-0xff). Like superglobals, the scope of a constant is global. Constants can be accessed from anywhere in a script without regard to scope. For more information on scope,
read the manual section on variable scope. Note: As of PHP 7.1.0, class constant may declare a visibility of protected or private, making them only available in the hierarchical scope of the class in which it is defined. wbcarts at juno dot com ¶ 10 years ago
//const MIN_VALUE = 0.0; RIGHT - Works both INSIDE and OUTSIDE of a class definition.
public static function
#Example 2:
#Example 1:
warwick dot jm dot barnes at gmail dot com ¶ 2 years ago
ewspencer at industrex dot com ¶ 19 years ago
gried at NOSPAM dot nsys dot by ¶ 6 years ago
hafenator2000 at yahoo dot com ¶ 17 years ago
Andreas R. ¶ 15 years ago
Raheel Khan ¶ 7 years ago
MAX_VALUE = 10; Sumon Mahmud (Abu Taleb) ¶ 2 years ago
storm ¶ 17 years ago
DEBUG) { jcastromail at yahoo dot es ¶ 4 years ago
mparsa1372 at gmail dot com ¶ 1 year ago
define('BOOK',100); php at webflips dot net ¶ 8 years ago
constant('echo'); // outputs 'My constant value'
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