Java Operator

Java Operators

Arithmetic Operator

Arithmetic operators are used for arithmetic operations in mathematical expressions. Following table shows list of arithmetic operators with its purpose.

Operator	Purpose
+	Addition
-	Subtraction (Also Unary Minus)
*	Multiplication
/	Division
++	Increment
--	Decrement
%	Modulus
+=	Addition Assignment
-=	Subtraction Assignment
*=	Multiplication Assignment
/=	Division Assignment
%=	Modulus Assignment

Operands of arithmetic operators must be of numeric type. Arithmetic operators may be applied on 'char' type also. Because 'char' type in java is, basically, subset of 'int' type.

Arithmetic Example

class ArithmeticExam {
public static void main(String args[]) {

int a = 10;
int b = 20;

int add, sub, mul, div, unaryminus;

add = a + b;
sub = b - a;
mul = a * b;
div = b / a;
unaryminus = -b;

System.out.println("add = " + add);
System.out.println("sub = " + sub);
System.out.println("mul = " + mul);
System.out.println("div = " + div);
System.out.println("unaryminus = " + unaryminus);
}
}

Output of the program

add = 30
sub = 10
mul = 200
div = 2
unaryminus = -20

Modulus Operator (%) Example

public class ModulusProg {
public static void main(String args[]) {
int k = 62;
double m = 35.5;
System.out.println("k mod 10 = " + k % 10);
System.out.println("m mod 10 = " + m % 10);
}
}

Output of the program

k mod 10 = 2
m mod 10 = 5.5

Assignment Operators Example

class AssignOperator {
public static void main(String args[]) {
int a = 10;
int b = 30;
int c = 20;
int d = 40;
int k = 45;

// following are assignment operators
a += 5;
b -= 4;
c *= 3;
d /= 2;
k %= 4;

System.out.println("a = " + a);
System.out.println("b = " + b);
System.out.println("c = " + c);
System.out.println("d = " + d);
System.out.println("k = " + k);
}
}

Output of the program

a = 15
b = 26
c = 60
d = 20
k = 1

Increment Operator (++) Example

Increment operator increases its operand by one.

x++;
is equivalent to
x = x + 1;

Increment operator can be used as both in prefix and postfix form.

In the prefix form, increment operator is written before the operand, such as:
++x;
In the postfix form, increment operator is written after the operand, such as:
x++;

Use of prefix and postfix form of increment operator is in the mathematical expression.
See the following assignment expression for both cases:
x = 1;
y = ++x;
In this prefix form , first value of x is incremented, then value of x is assigned to y variable.
Value of y is now 2 and value of x is now 2.

x = 1;
y = x++;
In this postfix form , first value of x is assigned to y variable, then value of x is incremented.
Value of y is now 1 and value of x is now 2.

Example:

class IncrementOp {
    public static void main(String args[]) {
        int x=1;
        int y;
        
        int m = 1;
        int n;
        
        y = ++x;
        
        n = m++;

        System.out.println("x = " + x);
        System.out.println("y = " + y);
        
        System.out.println("m = " + m);
        System.out.println("n = " + n);
    }
}

Output of the program

x = 2
y = 2
m = 2
n = 1

Decrement Operator (--) Example

Decrement operator decreases its operand by one.

x--;
is equivalent to
x = x - 1;

Decrement operator can be used as both in prefix and postfix form.

In the prefix form, decrement operator is written before the operand, such as:
--x;
In the postfix form, decrement operator is written after the operand, such as:
x--;

Use of prefix and postfix form of decrement operator is in the mathematical expresssion.
See the following assignment expression for both cases:
x = 1;
y = --x;
In this prefix form , first value of x is decremented, then value of x is assigned to y variable.
Value of y is now 0 and value of x is now 0.

x = 1;
y = x--;
In this postfix form , first value of x is assigned to y variable, then value of x is decremented.
Value of y is now 1 and value of x is now 0.

Example:

class DecrementOp {
    public static void main(String args[]) {
        int x=1;
        int y;
        
        int m = 1;
        int n;
        
        y = --x;
        
        n = m--;

        System.out.println("x = " + x);
        System.out.println("y = " + y);
        
        System.out.println("m = " + m);
        System.out.println("n = " + n);
    }
}

Output of the program

x = 0
y = 0
m = 0
n = 1

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