By the definition provided by Oracle –
"Operators are special symbols that perform specific operations on one, two, or three operands, and then return a result"
In other words, the operations you do with the variables in your Java Program are represented by some signs. They are called Operators.
For example, Assignment Operator (=). We use it for assigning some value in a variable.
Java provides many other operators. We can divide them according to their categories.

We will discuss about all these operators one by one.
Arithmetic Operators
Simple Arithmetic Operators
Operator
|
Result
|
Example
|
Meaning
|
+
|
Addition
|
int a = 1+1;
|
int a = 1+1;
|
-
|
Subtraction
|
int b = a-1;
|
int b = a-1;
|
*
|
Multiplication
|
int c = b*2;
|
int c = b*2;
|
/
|
Division
|
int d = c/2;
|
int d = c/2;
|
%
|
Modulus
|
int e = 10%2;
|
int e = 10%2;
|
++
|
Increment
|
a++; or ++a;
|
a = a+1;
|
--
|
Decrement
|
a--; Or --a;
|
a = a-1;
|
Though most of the operators are common in Arithmetic, Increment and Decrement operators are not.
Increment or decrement operators are used mainly in 2 ways. Either we can use it before the variable (++a) or after the variable (a++).
int f = (++a)+1;
This statement means, first increment the variable by 1(i.e. a=a+1).
Then execute the next statement,
i.e. int f = a+1;
int g = (a++)+1;
This statement means, first int g = a+1;
Then execute the next statement,
i.e. Make an increment of the variable by 1(i.e. a=a+1).
Similar applies for decrement operator.
--a or a—means, a=a-1;
Sample Program for Simple Arithmetic Expressions
Try It
public class SimpleArithmeticOperators
{
public static void main(String[] args) {
/**Simple Arithmetic Operators**/
//Addition
int a = 1+1;
System.out.println("Value of a is : "+ a);
//Subtraction
int b = a-1;
System.out.println("Value of b is : "+ b);
//Multiplication
int c = b*2;
System.out.println("Value of c is : "+ c);
//Division
int d = c/2;;
System.out.println("Value of d is : "+ d);
//Modulus
int e = 10%2;
System.out.println("Value of e is : "+ e);
//Increment Operator
a = 0;
int f = ++a;
System.out.println("Value of f is : "+ f);
a = 0;
System.out.println("Value of a before increment is : "+ a);
int g = a++;
System.out.println("Value of g is : "+ g);
System.out.println("Value of a after increment is : "+ a);
//Decrement Operator
a = 0;
int h = --a;
System.out.println("Value of h is : "+ h);
a = 0;
System.out.println("Value of a before decrement is : "+ a);
int i = a--;
System.out.println("Value of i is : "+ i);
System.out.println("Value of a after decrement is : "+ a);
}
}
The output will be - Click "Try It" button above

Arithmetic Assignment Operators
Operator
|
Result
|
Example
|
Meaning
|
+=
|
Addition Assignment
|
a+=2;
|
a = a+2;
|
-=
|
Subtraction Assignment
|
a-=3;
|
a = a-3;
|
*=
|
Multiplication Assignment
|
a*=4;
|
a = a*4;
|
/=
|
Division Assignment
|
a/=5;
|
a = a/5;
|
%=
|
Modulus Assignment
|
a%=6
|
a = a%6;
|
Arithmetic Assignment Operators are quite straight forward and self-explanatory too!
Sample Program for Arithmetic Assignments - Click Try It to compile the below code
Try It
public class ArithmeticAssignment {
public static void main(String[] args) {
int a = 10;
System.out.println("value of variable before assignment: "+ a);
a+= 2;
System.out.println("value of variable after first assignment: "+ a);
a-=3;
System.out.println("value of variable after second assignment: "+ a);
a*=4;
System.out.println("value of variable after third assignment: "+ a);
a/=5;
System.out.println("value of variable after fourth assignment: "+ a);
a%=6;
System.out.println("value of variable after fifth assignment: "+ a);
}
}
The output of this program is – Cick Try It Button above to Compile

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