PHP Constants

PHP ConstantsBy Daysi CastroLopezClass 336

Constants are variablesConstants are variables except that once they are defined they cant be changed or undefined.W3schools.com defines it as:A constant is an identifier (name) for a simple value. The value cannot be changed during the script.A valid constant name starts with a letter or underscore. (no $ sign before the constant name).Note:Unlike variables, constants are automatically global across the entire script.

Create a PHP constant You can create a constant by using the define () function.Use the define function to specify the name and value of a constant. (name, value, case-insensitive). Many programmers use capital letters to name constants so they stand out.Note: Since a constant can not be change you do not use a $ sign before its name when you declare it or (use it).

Parameters

name: Specifies the name of the constantvalue: Specifies the value of the constantcase-insensitive: Specifies whether the constant name should be case-insensitive. Default is false

How to declare constants

Examples: define(male, m) ; // a string constant

define(PI, 3.14159) ; // a double constant

PHP Constant ExamplesPHP source

Result

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Sources

Harris, Ray and Murach, Joel Section 2: Master PHP Programming. Murachs PHP & MySQL. CA : Mike Murach and Associates, INC 2014.http://www.W3school.com/php/php_constants