Variable in Java is a data container that stores the data values during Java program execution. Variable is a memory location name of the data. . Every variable is assigned data type which designates the type and quantity of value it can hold. The Java variables have three types of variables - local, instance and static.
There are types of variables in Java programming language:
- Instance Variables (Non-Static Fields)
- Class Variables (Static Fields)
- Local Variables
- Parameters
1) Local Variables
Local Variables are a variable that are declared inside the body of a method. A local variable declared inside the body of the method is called local variable. You can use this variable only within that method and the other methods in the class aren't even aware that the variable exists.
A local variable cannot be defined with "static" keyword
2) Instance Variables
A variable declared inside the class but outside the body of the method, is called instance variable. It is not declared as static.
It is called instance variable because its value is instance specific and is not shared among instances.
3) Static Variables
Static variables are initialized only once, at the start of the program execution. These variables should be initialized first, before the initialization of any instance variables.
Example: Types of Variables in Java
static int ab = 91; //static variable
int intiger = 7; //instance variable
void method() {
int a = 9; //local variable
Java literals
Literals are data used for representing values. They can be used directly in the code. For example,
int var = 89;
float floatvar = 89.98f;
Here, 89, 89.98f, are literals.
Here are different types of literals in Java.
1. Boolean Literals
In Java, boolean literals are used to initialize boolean data types. They can store two values: true and false. For example,
boolean holiday = false;
boolean holiday = true;
2. Integer Literals
An integer literal is a numeric value. There are 4 types of integer literals in Java:
1. binary (base 2)
2. decimal (base 10)
3. octal (base 8)
4. hexadecimal (base 16)
For example:
// binary Number
int binaryNumber = 0b110;
// octal Number
int OctalNumber = 027;
// decimal Number
int DecNumber = 34;
// hexadecimal Number
int HexNumber = 0x2Fsd3; // 0x represents hexadecimal
// binary
int BinNumber = 0b010; // 0b represents binary
In Java, binary starts with 0b, octal starts with 0, and hexadecimal starts with 0x.
3. Floating-point Literals
A floating-point literal is a numeric. For example,
float $Age = 87.6f;
double doublevar = 976.9;
4. Character Literals
Character literals are unicode character enclosed inside single quotes. For example,
char A = 'a';
5. String literals
A string literal is a sequence of characters enclosed inside double-quotes. For example,
String var = "Programming";
String va2 = "androidpro.in";
Here, Programming and androidpro.in are two string literals.
