PHP constants are name or identifier that can’t be changed at the time of the execution of the script. we used PHP constants in 2 ways:
- Using define() function
- Using const keyword
PHP constants follow the same PHP variable rules. For example, it can be started with a letter or underscore only.
Conventionally, PHP constants should be defined in uppercase letters.
PHP constant: define()
Let’s see the syntax of define() function in PHP.
define(name, value, case-insensitive)
- name: specifies the constant name
- value: specifies the constant value
- case-insensitive: Default value is false.
<?php define("MESSAGE","Hello JavaTpoint PHP"); echo MESSAGE; ?>
Hello JavaTpoint PHP
The const keyword defines constants at compile time. It is a language construct not a function.
It is a bit faster than define().
It is always case sensitive.
<?php const MESSAGE="Hello const by JavaTpoint PHP"; echo MESSAGE; ?>
Hello const by JavaTpoint PHP