Operators

Definition

Operators are symbols used to perform operations on variables (operands).

Types of Operators

1. Arithmetic Operators

2. Assignment Operator

3. Relational Operators

4. Logical Operators

5. Bitwise Operators

6. Ternary Operator

7. Increment/Decrement Operator

8. new Operator

9. instanceof Operator

1. Arithmetic Operators

Used to perform mathematical operations.

OperatorDescription => + Addition - Subtraction * Multiplication / Division % Modulus

Example

java

int a = 100;
int b = 20;

System.out.println(a + b);
System.out.println(a - b);
System.out.println(a * b);
System.out.println(a / b);
System.out.println(a % b);

Note: Arithmetic operations cannot be performed on boolean values.

2. Assignment Operator (=)

Used to assign value from right side to left side variable.

Syntax

java

variable = value;

Type Casting

Definition

Type casting is converting one data type into another compatible type.

Types of Type Casting

1. Implicit Type Casting (Widening)

• Done automatically by JVM

• When destination type is larger than source

java

byte b = 10;
int a = b;

2. Explicit Type Casting (Narrowing)

• Done manually

• May cause data loss

java

int a = 130;
byte b = (byte) a;

3. Relational Operators

Used to compare two values.
Result is always boolean (true/false).

OperatorMeaning > Greater than < Less than >= Greater than equal <= Less than equal ==Equal !=Not equal

Example

java

int a = 20;
int b = 10;

System.out.println(a > b);
System.out.println(a == b);

Note: Relational operators cannot be used with boolean values (except == and !=).

4. Logical Operators

Used with boolean expressions.

1. Logical AND (&&)

• Returns true only if both conditions are true

java

System.out.println(true && true); // true
System.out.println(true && false); // false
System.out.println(false && true); // false
System.out.println(false && false); // false

2. Logical OR (||)

• Returns true if at least one condition is true

java

System.out.println(true || true); // true
System.out.println(true || false); // true
System.out.println(false || true); // true
System.out.println(false || false); // false

3. Logical NOT (!)

• Reverses the boolean value

java

System.out.println(!true); // false

Short-Circuit Behavior

• && → stops if first condition is false

• || → stops if first condition is true

5. Bitwise Operators

Operate on binary (bits).

Operate on binary (bits).

OperatorMeaning & -> AND | -> OR ^ -> XOR << -> Left Shift >> -> Right Shift >>> -> Unsigned Right Shift ~ -> Complement

Example

java

int a = 5;  // 0101
int b = 7;  // 0111

System.out.println(a & b); // 0101 = 5
System.out.println(a | b); // 0111 = 7
System.out.println(a ^ b); // 0010 = 2

6. Ternary Operator

Short form of if-else.

Syntax

java

condition ? value1 : value2;

Example

java

int a = 10;
int b = 20;

String result = (a > b) ? "A is greater" : "B is greater";

7. Increment / Decrement Operators

Increment (++)

Pre-increment

java

int x = 10;
int y = ++x; // x first increases

Post-increment

java

int x = 10;
int y = x++; // x increases later

Decrement (--)

Pre-decrement

java

int x = 10;
int y = --x;

Post-decrement

java

int x = 10;
int y = x--;

8. new Operator

Used to create objects and allocate memory in heap.

Example

java

Test t1 = new Test();

• new → allocates memory

• Test() → constructor call

• t1 → reference variable

9. instanceof Operator

Used to check object type.

Example

java

if (obj instanceof String) {
    System.out.println("It is a String");