Example
Define a case-sensitive constant:
html
<?php
define("GREETING","Hello you! How are you today?");
echo constant("GREETING");
?>
Definition and Usage
The define() function defines a constant.
Constants are much like variables, except for the following differences:
- A constant's value cannot be changed after it is set
- Constant names do not need a leading dollar sign ($)
- Constants can be accessed regardless of scope
Syntax
text
define(name, value, case_insensitive)
Parameter Values
| Parameter | Description |
|---|---|
| name | Required. Specifies the name of the constant |
| value | Required. Specifies the value of the constant. |
| case_insensitive | Optional. Specifies whether the constant name should be case-insensitive. Possible values: TRUE - Case-insensitive (deprecated in PHP 7.3) FALSE - Case-sensitive (this is default) |
Technical Details
| Return Value: | Returns TRUE on success or FALSE on failure |
|---|---|
| PHP Version: | 4+ |
| Changelog: | PHP 8.1: The value parameter can now also be an object.PHP 7.3: The case-insensitive parameter is deprecated.PHP 7: The value parameter can also be an array.PHP 5: The value parameter must be a string, integer, float, boolean or NULL. |