PHP Introduction, Variable declaration and Variable Function of PHP

What is a PHP?

• PHP means Personal Home Page.
• Then after it is known as a ”Hypertext PreProcessor”.
• It is developed by “Rasmas Lerdorf in 1994”.
• It is server side scripting language which is used to create dynamic website.
• PHP script also executed on this server.
• It support many database like mysql, oracle, odbc, etc.
• It is open source software.
• It support multiple plateform.
• PHP syntax is easy to understand.

Syntax

Variable Declaration in PHP

• In the PHP variable declaration is easy.
• PHP is a loosely type language. 
• In PHP for declare a Variable  ($) Dollar Sign is compulsory. 
• In the PHP for declare a variable datatype declare not be compulsory. 
• You can place a variable any where in the script using ($) Dollar Sign.

Syntax

=> Variable Function fo PHP

We can use a Varible function for perform operation on Variable.

• Gettype:- Use to get the datatype of Variable.

                 Syntax

                 gettype(variable_name);

• Settype:- Use to set the datatype of variable.

                Syntax

                settype(Varible_name,Varible_type);

• Isset:- Used to check the variable is set or not.

1. It return true or false.
2. If variable is set then return true otherwise false.

               Syntax

               isset(variable1, variable2,…….);

• Unset:- Used to destroy given Varible.

               Syntax

               unset(Variable1, Variable2,…………);

•  Strval:- Convert a value of variable into a String.

                    Syntax

                    strval(Variable_name);

•  Floatval:- Convert a value of variable into a Float.

                    Syntax

                    floatval(Variable_name);

• Intval:- Used to get the value of a variable.

                    Syntax

                    intval(Variable_name);