How to use php define function

php define function is used to define a constant. Its syntax is define(name, value, case_insensitive). The parameter name is required and specifies the name of the constant; value is required and specifies the value of the constant.

#How to use the php define function?

Definition and usage

define() function defines a constant.

Constants are similar to variables, except that:

● After setting, the value of the constant cannot be changed

● Constant names do not require a dollar sign ($) at the beginning

● Scope does not affect access to constants

● Constant values ​​can only be strings and numbers

Syntax

define(name,value,case_insensitive)

Parameters

name is required. Specifies the name of the constant.

value Required. Specifies the value of the constant. PHP7 supports arrays, examples are as follows:

case_insensitive Optional. Specifies whether constant names are case-sensitive. Possible values:

TRUE - case insensitive

FALSE - default. Case sensitive

Return value:

Returns TRUE if successful, returns FALSE if failed.

PHP Version: 4

Example 1

Define a case-insensitive constant:

Output:

Hello you! How are you today?

Example 2

Define a case-sensitive constant:

Output:

Hello you! How are you today?

The above is the detailed content of How to use php define function. For more information, please follow other related articles on the PHP Chinese website!