OBJECT ORIENTED PROGRAMMING THROUGH JAVA : Unit - 1 : Introduction to Operators and Types of Operators in Java

Operators in Java – Complete Detailed Notes

Operators in Java are special symbols used to perform operations on variables and values. They are essential for building expressions and controlling logic.

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Classification of Java Operators

Java operators are broadly categorized into the following:

1. Arithmetic Operators

2. Relational (Comparison) Operators

3. Logical Operators

4. Assignment Operators

5. Unary Operators

6. Bitwise Operators

7. Ternary Operator

8. Shift Operators

9. Instanceof Operator

10. Type Cast Operator

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1. Arithmetic Operators

Used to perform basic mathematical operations.

Operator	Description	Example	Result
+	Addition	a + b	Sum of a and b
-	Subtraction	a - b	Difference of a and b
*	Multiplication	a * b	Product of a and b
/	Division	a / b	Quotient
%	Modulus (Remainder)	a % b	Remainder of a / b

Example:

int a = 10, b = 3;
System.out.println(a + b); // Output: 13
System.out.println(a % b); // Output: 1

Example program
public class ArithmeticDemo {
    public static void main(String[] args) {
        int a = 15, b = 4;
        System.out.println("Addition: " + (a + b));        // 19
        System.out.println("Subtraction: " + (a - b));     // 11
        System.out.println("Multiplication: " + (a * b));  // 60
        System.out.println("Division: " + (a / b));        // 3
        System.out.println("Modulus: " + (a % b));         // 3
    }
}

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2. Relational (Comparison) Operators

Used to compare two values. Returns a boolean (true or false).

Operator	Description	Example
==	Equal to	a == b
!=	Not equal to	a != b
>	Greater than	a > b
<	Less than	a < b
>=	Greater than or equal	a >= b
<=	Less than or equal	a <= b

Example Program

public class RelationalDemo {

    public static void main(String[] args) {

        int x = 10, y = 20;

        System.out.println("x == y: " + (x == y)); // false

        System.out.println("x != y: " + (x != y)); // true

        System.out.println("x > y: " + (x > y));   // false

        System.out.println("x < y: " + (x < y));   // true

        System.out.println("x >= y: " + (x >= y)); // false

        System.out.println("x <= y: " + (x <= y)); // true

    }

}

3. Logical Operators

Used to combine multiple boolean expressions.

Operator	Description	Example
&&	Logical AND	a > 5 && b < 10
`		`
!	Logical NOT	!(a == b)

Example Program

 public class LogicalDemo {

    public static void main(String[] args) {

        int a = 5, b = 10;

        boolean result1 = (a < b) && (b > 5);

        boolean result2 = (a > b) || (b == 10);

        boolean result3 = !(a == b);

         System.out.println("AND: " + result1); // true

        System.out.println("OR: " + result2);  // true

        System.out.println("NOT: " + result3); // true

    }

}

4. Assignment Operators

Used to assign values to variables.

Operator	Description	Example
=	Assign	a = 10
+=	Add and assign	a += 5 → a = a + 5
-=	Subtract and assign	a -= 3
*=	Multiply and assign	a *= 2
/=	Divide and assign	a /= 4
%=	Modulus and assign	a %= 3

Example Program

public class AssignmentDemo {

    public static void main(String[] args) {

        int a = 10;

        a += 5;  // a = a + 5

        System.out.println("a += 5: " + a);  // 15

        a *= 2;  // a = a * 2

        System.out.println("a *= 2: " + a);  // 30

        a -= 10; // a = a - 10

        System.out.println("a -= 10: " + a); // 20

    }

}

5. Unary Operators

Operate on a single operand.

Operator	Description	Example
+	Unary plus	+a
-	Unary minus	-a
++	Increment	++a, a++
--	Decrement	--a, a--
!	Logical complement	!true → false

Pre-increment and Post-increment:

int a = 5;
System.out.println(++a); // 6 (pre-increment)
System.out.println(a++); // 6 (post-increment, then becomes 7)

Example Program
public class UnaryDemo {
    public static void main(String[] args) {
        int x = 5;
        System.out.println("x: " + x);           // 5
        System.out.println("++x: " + ++x);       // 6
        System.out.println("x++: " + x++);       // 6 (then x becomes 7)
        System.out.println("--x: " + --x);       // 6
        System.out.println("x--: " + x--);       // 6 (then x becomes 5)
        System.out.println("Final x: " + x);     // 5
    }
}

6. Bitwise Operators

Used to perform operations on bits.

Operator	Description	Example
&	Bitwise AND	a & b
`	`	Bitwise OR
^	Bitwise XOR	a ^ b
~	Bitwise complement	~a

Example Program

public class BitwiseDemo {

    public static void main(String[] args) {

        int a = 5;  // 0101

        int b = 3;  // 0011

        System.out.println("a & b: " + (a & b)); // 1 (0001)

        System.out.println("a | b: " + (a | b)); // 7 (0111)

        System.out.println("a ^ b: " + (a ^ b)); // 6 (0110)

        System.out.println("~a: " + (~a));       // -6

    }

}

7. Ternary Operator

Also known as the conditional operator. It's a shortcut for if-else.

Syntax:

condition ? expression1 : expression2

Example:

int a = 10, b = 20;
int max = (a > b) ? a : b; // max = 20

Example Program

public class TernaryDemo {
    public static void main(String[] args) {
        int a = 10, b = 20;
        int max = (a > b) ? a : b;
        System.out.println("Maximum is: " + max); // 20
    }
}

8. Shift Operators

Used to shift bits left or right.

Operator	Description	Example
<<	Left shift	a << 2
>>	Right shift	a >> 2
>>>	Unsigned right shift	a >>> 2

Example Program

public class ShiftDemo {

    public static void main(String[] args) {

        int a = 8; // 1000

        System.out.println("a << 2: " + (a << 2)); // 32

        System.out.println("a >> 2: " + (a >> 2)); // 2

        System.out.println("a >>> 2: " + (a >>> 2)); // 2

    }

}

9. instanceof Operator

Checks if an object is an instance of a specific class or subclass.

String s = "Hello";
System.out.println(s instanceof String); // true

Example Program
public class InstanceofDemo {
    public static void main(String[] args) {
        String s = "Hello";
        System.out.println(s instanceof String); // true
    }
}

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10. Type Cast Operator

Used to convert one data type into another.

Example:

int a = 10;
double b = (double) a; // Type casting int to double


Example Program
public class TypeCastDemo {
    public static void main(String[] args) {
        int a = 10;
        double d = (double) a;
        System.out.println("Converted to double: " + d); // 10.0
    }
}

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Summary Table of Java Operators

Type	Operators
Arithmetic	+, -, *, /, %
Relational	==, !=, >, <, >=, <=
Logical	&&, `
Assignment	=, +=, -=, *=, /=, %=
Unary	+, -, ++, --, !
Bitwise	&, `
Shift	<<, >>, >>>
Ternary	condition ? trueVal : falseVal
instanceof	object instanceof ClassName
Type Cast	(targetType) value

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