Operators allow you to perform operations on values and variables. Java has a wide range of operators grouped by purpose.
Arithmetic Operators
Used for basic math operations.
int a = 10, b = 3;
System.out.println(a + b); // Addition
System.out.println(a - b); // Subtraction
System.out.println(a * b); // Multiplication
System.out.println(a / b); // Division
System.out.println(a % b); // Modulus (remainder)
Comparison Operators
Used to compare two values. These always return a boolean (true or false).
int x = 5, y = 8;
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 >= y); // false
System.out.println(x <= y); // true
Logical Operators
Used to combine multiple boolean expressions.
boolean a = true;
boolean b = false;
System.out.println(a && b); // AND → false
System.out.println(a || b); // OR → true
System.out.println(!a); // NOT → false
Assignment Operators
Used to assign or update values in variables.
int n = 10;
n += 5; // Same as n = n + 5 → 15
n -= 3; // Now n = 12
n *= 2; // Now n = 24
n /= 4; // Now n = 6
Other Useful Operators
Increment/Decrement
int i = 0;
i++; // i becomes 1
i--; // i goes back to 0
Ternary Operator
A shortcut for simple if-else.
int age = 20;
String result = (age >= 18) ? "Adult" : "Minor";
System.out.println(result); // Adult
Java also has bitwise, instanceof, and other advanced operators, which we’ll touch upon later as needed.