A PHP Error was encountered

Severity: 8192

Message: Return type of CI_Session_files_driver::open($save_path, $name) should either be compatible with SessionHandlerInterface::open(string $path, string $name): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice

Filename: drivers/Session_files_driver.php

Line Number: 132

Backtrace:

File: /home/infovistar/public_html/application/controllers/php/Php.php
Line: 7
Function: __construct

File: /home/infovistar/public_html/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: 8192

Message: Return type of CI_Session_files_driver::close() should either be compatible with SessionHandlerInterface::close(): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice

Filename: drivers/Session_files_driver.php

Line Number: 292

Backtrace:

File: /home/infovistar/public_html/application/controllers/php/Php.php
Line: 7
Function: __construct

File: /home/infovistar/public_html/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: 8192

Message: Return type of CI_Session_files_driver::read($session_id) should either be compatible with SessionHandlerInterface::read(string $id): string|false, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice

Filename: drivers/Session_files_driver.php

Line Number: 166

Backtrace:

File: /home/infovistar/public_html/application/controllers/php/Php.php
Line: 7
Function: __construct

File: /home/infovistar/public_html/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: 8192

Message: Return type of CI_Session_files_driver::write($session_id, $session_data) should either be compatible with SessionHandlerInterface::write(string $id, string $data): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice

Filename: drivers/Session_files_driver.php

Line Number: 235

Backtrace:

File: /home/infovistar/public_html/application/controllers/php/Php.php
Line: 7
Function: __construct

File: /home/infovistar/public_html/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: 8192

Message: Return type of CI_Session_files_driver::destroy($session_id) should either be compatible with SessionHandlerInterface::destroy(string $id): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice

Filename: drivers/Session_files_driver.php

Line Number: 315

Backtrace:

File: /home/infovistar/public_html/application/controllers/php/Php.php
Line: 7
Function: __construct

File: /home/infovistar/public_html/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: 8192

Message: Return type of CI_Session_files_driver::gc($maxlifetime) should either be compatible with SessionHandlerInterface::gc(int $max_lifetime): int|false, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice

Filename: drivers/Session_files_driver.php

Line Number: 356

Backtrace:

File: /home/infovistar/public_html/application/controllers/php/Php.php
Line: 7
Function: __construct

File: /home/infovistar/public_html/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: ini_set(): Session ini settings cannot be changed after headers have already been sent

Filename: Session/Session.php

Line Number: 282

Backtrace:

File: /home/infovistar/public_html/application/controllers/php/Php.php
Line: 7
Function: __construct

File: /home/infovistar/public_html/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_set_cookie_params(): Session cookie parameters cannot be changed after headers have already been sent

Filename: Session/Session.php

Line Number: 294

Backtrace:

File: /home/infovistar/public_html/application/controllers/php/Php.php
Line: 7
Function: __construct

File: /home/infovistar/public_html/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: ini_set(): Session ini settings cannot be changed after headers have already been sent

Filename: Session/Session.php

Line Number: 304

Backtrace:

File: /home/infovistar/public_html/application/controllers/php/Php.php
Line: 7
Function: __construct

File: /home/infovistar/public_html/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: ini_set(): Session ini settings cannot be changed after headers have already been sent

Filename: Session/Session.php

Line Number: 314

Backtrace:

File: /home/infovistar/public_html/application/controllers/php/Php.php
Line: 7
Function: __construct

File: /home/infovistar/public_html/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: ini_set(): Session ini settings cannot be changed after headers have already been sent

Filename: Session/Session.php

Line Number: 315

Backtrace:

File: /home/infovistar/public_html/application/controllers/php/Php.php
Line: 7
Function: __construct

File: /home/infovistar/public_html/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: ini_set(): Session ini settings cannot be changed after headers have already been sent

Filename: Session/Session.php

Line Number: 316

Backtrace:

File: /home/infovistar/public_html/application/controllers/php/Php.php
Line: 7
Function: __construct

File: /home/infovistar/public_html/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: ini_set(): Session ini settings cannot be changed after headers have already been sent

Filename: Session/Session.php

Line Number: 317

Backtrace:

File: /home/infovistar/public_html/application/controllers/php/Php.php
Line: 7
Function: __construct

File: /home/infovistar/public_html/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: ini_set(): Session ini settings cannot be changed after headers have already been sent

Filename: Session/Session.php

Line Number: 375

Backtrace:

File: /home/infovistar/public_html/application/controllers/php/Php.php
Line: 7
Function: __construct

File: /home/infovistar/public_html/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_set_save_handler(): Session save handler cannot be changed after headers have already been sent

Filename: Session/Session.php

Line Number: 110

Backtrace:

File: /home/infovistar/public_html/application/controllers/php/Php.php
Line: 7
Function: __construct

File: /home/infovistar/public_html/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Session cannot be started after headers have already been sent

Filename: Session/Session.php

Line Number: 143

Backtrace:

File: /home/infovistar/public_html/application/controllers/php/Php.php
Line: 7
Function: __construct

File: /home/infovistar/public_html/index.php
Line: 315
Function: require_once

PHP Constants
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PHP Constants

PHP Constants

Constants are PHP containers that remain constant and never change. Constants are used for data that is unchanged at multiple places within a program. Variables are temporary storage while Constants are permanent. Use Constants for values that remain fixed and referenced multiple times.

Rules for defining constant

PHP constants can be defined in 2 ways:

  • Using define() function
  • Using const keyword

Using define() function

define(name, value, case-insensitive)

name: Name of the constant

value: Value of the constant

case-insensitive: Wheather a constant is case-insensitive, The default value is false.

Using const keyword

The const keyword defines constants at compile time. It is a language construct, not a function.

<?php
const MESSAGE = "Welcome to PHP";  
echo MESSAGE;  
?>