PHP Constant

 <?php

// PHP CONSTANT

/*

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

To create a constant, use the define() function.Constants are like variables except that once they are defined they cannot be changed or undefined.

Syntax

define(name, value, case-insensitive)

*/

define("HELLO", "Hi there, This is Priya");

echo HELLO;

echo "<br>";

// case-insensitive constant name

define("GREETING", "Welcome to session", true);

echo greeting;

echo "<br>";

//Create an Array constant:

define("cars", [

  "Alfa Romeo",

  "BMW",

  "Toyota"

]);

echo cars[0];

echo "<br>";

//Constants are Global

//Constants are automatically global and can be used across the entire script.

//This example uses a constant inside a function, even if it is defined outside the function:

define("GREETING", "Welcome to session!");

function myTest() {

  echo GREETING;

}

myTest();

?>