Quick introduction to Java Programming language - Part 1

Each and every variable in the Java must have a data type. The memory allocation to the variable is based on the data type.By assigning data types to variables, user can store integers, characters or decimalsin these variables.

Categories of data types in Java:

• Primitive Data Types
• Derived/Reference/Object Data Types

Primitive Data Type: is the basic type, which is inbuilt data type of java.

• Variables declared with primitive data type are known as primitive data type.

Primitive data types are:

Syntax:  data-type variable name;

Example:  int age;

Derived Data Types:

This is customized data type of java.

• Variables declared with deriveddata type are known as derived data type.
• Mainly used to store the reference/address of an object created,Class objects, and various type of array variables come under reference data type.

Example:

Creating object for Account class

Account a1 = new Account(“Savings”);

Here, a1 is derived data type. 

Java supports few escape sequences. They are:

• \n: It is used to points the cursor to Newline
• \r: It is for carriage return
• \s: It is for space
• \\: backslash
• \t: tab
• \f: It is for formfeed
• \ddd: It is for octal character (ddd)
• \": It is used for double quote
• \': It is used for single quote
• \uxxx: It is for Hexadecimal UNICODE character (xxxx)