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PHP Quiz PHP CertificatePHP define() Function
Complete PHP Misc Reference
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
- Constant values can only be strings and numbers
Syntax
define(name,value,case_insensitive)
| 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. If set to TRUE, the constant will be case-insensitive. Default is FALSE (case-sensitive) |
Example 1
Define a case-sensitive constant:
<?php
define("GREETING","Hello you! How are you today?");
echo constant("GREETING");
?>
define("GREETING","Hello you! How are you today?");
echo constant("GREETING");
?>
The output of the code above will be:
Hello you! How are you today?
Example 2
Define a case-insensitive constant:
<?php
define("GREETING","Hello you! How are you today?",TRUE);
echo constant("greeting");
?>
define("GREETING","Hello you! How are you today?",TRUE);
echo constant("greeting");
?>
The output of the code above will be:
Hello you! How are you today?
Complete PHP Misc Reference
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