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Operator

Operators in Java are special symbols used to perform operations on variables and values. They are grouped into several categories based on the type of operation they perform.

Arithmetic Operators​

Used to perform basic math operations.

+   // Addition:       a + b
-   // Subtraction:    a - b
*   // Multiplication: a * b
/   // Division:       a / b
%   // Modulus:        a % b (remainder)

Example:

int a = 10, b = 3;
System.out.println(a + b);  // 13
System.out.println(a - b);  // 7
System.out.println(a * b);  // 30
System.out.println(a / b);  // 3
System.out.println(a % b);  // 1

2. Relational (Comparison) Operators​

Used to compare two values and return a boolean.

==   // Equal to
!=   // Not equal to
>    // Greater than
<    // Less than
>=   // Greater than or equal to
<=   // Less than or equal to

Example:

int x = 5, y = 10;
System.out.println(x == y);  // false
System.out.println(x != y);  // true
System.out.println(x > y);   // false
System.out.println(x < y);   // true
System.out.println(x >= 5);  // true
System.out.println(x <= 3);  // false

3. Logical Operators​

Used to combine multiple boolean expressions.

&&   // Logical AND
||   // Logical OR
!    // Logical NOT

Example:

boolean p = true, q = false;
System.out.println(p && q);  // false
System.out.println(p || q);  // true
System.out.println(!p);      // false

4. Assignment Operators​

Used to assign values to variables.

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

Example:

int n = 5;
n += 3;  // n = 8
n -= 2;  // n = 6
n *= 4;  // n = 24
n /= 6;  // n = 4
n %= 3;  // n = 1
System.out.println(n);  // 1

5. Unary Operators​

Work with a single operand.

+   // Unary plus (positive)
-   // Unary minus (negative)
++  // Increment (pre/post)
--  // Decrement (pre/post)
!   // Logical NOT

Example:

int m = 7;
System.out.println(+m);   // 7
System.out.println(-m);   // -7
System.out.println(++m);  // 8 (pre-increment)
System.out.println(m--);  // 8 (post-decrement, then m becomes 7)
System.out.println(m);    // 7
boolean flag = false;
System.out.println(!flag); // true

6. Bitwise Operators​

Operate on bits (0s and 1s).

&    // AND
|    // OR
^    // XOR
~    // Bitwise complement
<<   // Left shift
>>   // Right shift
>>>  // Unsigned right shift

Example:

int u = 5;   // 0101
int v = 3;   // 0011
System.out.println(u & v);   // 1  (0001)
System.out.println(u | v);   // 7  (0111)
System.out.println(u ^ v);   // 6  (0110)
System.out.println(~u);      // -6 (inverts bits)
System.out.println(u << 1);  // 10 (1010)
System.out.println(u >> 1);  // 2  (0010)

7. Ternary Operator​

A shortcut for if-else:

condition ? trueValue : falseValue

int max = (a > b) ? a : b;

Example:

int a = 20, b = 15;
int max = (a > b) ? a : b;
System.out.println("Max: " + max); // Max: 20

8. instanceof Operator​

Checks if an object is an instance of a class.

if (obj instanceof String) {
    System.out.println("It's a string!");
}

Example:

String text = "Hello";
System.out.println(text instanceof String);  // true
Object obj = 123;
System.out.println(obj instanceof Integer);  // true