Today we are going to cover this topics,tags of PHP and their syntax,variables in PHP,data types of PHP.

Tags of PHP:

We mainly use 4 tags in PHP for any code and expressions.
They are

• Default tag or Standard tag


• Short tag


• Asp style tag


• Script tag

Default tag:

syntax:

Short tag:

syntax:

Asp tag:

syntax:
<% …........... %>

Script tag:

syntax:

Variable in PHP:

• Variables must be start with $ sign.


• Variables name first character must be alphabet.


• Variables in PHP follows alpha numeric concept.


• Variables are case sensitive.


• We can join one or more character or words as like as variable name through _(under score).

Ex:
int join_sal=100;
(or)
int joinSal=100;


• A space and special symbol not allow with variable name.
  Variable must end with semicolon.

Data type :

Data type is used to define while typing of values are specific in a variable.
There are six standard data types used in PHP.

• Integer (whole number, Ex : 54534)


• Float/Double (real number, Ex :1.677,24.786)


• String (any type of character which includes within single quotes. Ex : 'f',”regfd242”)


• Array (It can store one or more value in single memory space)


• Boolean (True or False statement)


• Object

In PHP we use two specific data types

• Null (undefined variables has null value .Ex : $x)


• Resource

In C,C++,JAVA we have restriction to define a variable with data type .But in PHP we are free to define variable without data type. PHP variable is also known as dynamic variable