What is the meaning of a final class and a final method?
The final keyword in a method declaration indicates that the method cannot be overridden by subclasses. A class that is declared final cannot be subclassed. This is particularly useful when we are creating an immutable class like the String class.Properties cannot be declared final, only classes and methods may be declared as final.
Where sessions stored in PHP ?
PHP sessions are stored on the server generally in text files in a temp directory of the server.
That file is not accessible from the outside world. When we create a session PHP create a unique session id that is shared by the client by creating a cookie on the client’s browser. That session id is sent by the client browser to the server each time when a request is made and the session is identified.
The default session name is “PHPSESSID”.
What are different types of errors available in Php ?
There are 13 types of errors in PHP, We have listed all below
- E_ERROR: A fatal error that causes script termination.
- E_WARNING: Run-time warning that does not cause script termination.
- E_PARSE: Compile time parse error.
- E_NOTICE: Run time notice caused due to error in code.
- E_CORE_ERROR: Fatal errors that occur during PHP initial startup.
(installation) - E_CORE_WARNING: Warnings that occur during PHP initial startup.
- E_COMPILE_ERROR: Fatal compile-time errors indication problem with script.
- E_USER_ERROR: User-generated error message.
- E_USER_WARNING: User-generated warning message.
- E_USER_NOTICE: User-generated notice message.
- E_STRICT: Run-time notices.
- E_RECOVERABLE_ERROR: Catchable fatal error indicating a dangerous error
- E_ALL: Catches all errors and warnings.
How to get length of an array in PHP ?
PHP count function is used to get the length or numbers of elements in an array
<?php // initializing an array in PHP $array=['a','b','c']; // Outputs 3 echo count($array); ?>
What are the encryption functions available in PHP ?
crypt(), Mcrypt(), hash() are used for encryption in PHP
What is Cross-site scripting?
Cross-site scripting (XSS) is a type of computer security vulnerability typically found in web applications. XSS enables attackers to inject client-side script into web pages viewed by other users. A cross-site scripting vulnerability may be used by attackers to bypass access controls such as the same-origin policy.
What are the difference between echo and print?
Difference between echo and print in PHP
echo in PHP
- echo is language constructs that display strings.
- echo has a void return type.
- echo can take multiple parameters separated by comma.
- echo is slightly faster than print.
Print in PHP
- print is language constructs that display strings.
- print has a return value of 1 so it can be used in expressions.
- print cannot take multiple parameters.
- print is slower than echo.
