Constant of PHP

PHP constant variable ka syntax es prakar likha jaata Hain:-

define (name, value, case-insensitive)

Ex- define (name, 500)

echo num;

es tarah se likhne par varible ko nahi badla ja sakta hain . par yah case-sensitive hota hain .

es kami ko door Karne Ke Liye , 500 ke aage [true] likha jata hain :-

define (num ,500, true)

echo NUM;

es tarah se likhne par varible ko bade akshar me likh kar print kara Sakte Hain Aur koi Erro Bhi Nahi Hoga .

Agar parameter me true nahi dete hain to wah Default roop me 'False ' hota hain.

Note: -

Ex: -

<?php

define ("test" ,50) ;

define ("test", 10) ;

echo test;

?>

es trah se likhne par error dekhne ko milta hain kyonki constant value ko dobara define nahi kiya ja sakta hain.

Output: -

<?php

define ("_test" ,50) ;

//define ("test", 10) ;

echo _test;

?>

es tarah se likhne par bhi hamara jo code hain proper work karega.

output: -

Agar koi numeric value laga de to erro aa sakta hain , es tarah se :-

Note: -

constant varible ko dobara reAssign aur Redefine nahi kar sakte hain.

Par ese nimn tarike use Kiya ja Sakta Hain: -

PHP