➕ Lesson 4: Java Operators
⏱️ Estimated time: 20 minutes | Difficulty: Beginner
Logic and Math
Java operators are special symbols used to perform operations on variables and values.
Arithmetic Operators
int a = 10, b = 3;
a + b // 13 Addition
a - b // 7 Subtraction
a * b // 30 Multiplication
a / b // 3 Integer division (truncates!)
a % b // 1 Modulus (remainder)
// Watch out for integer division!
10 / 3 // 3 (not 3.333!)
10.0 / 3 // 3.333... (use double for decimal)
// Increment / Decrement
int x = 5;
x++; // x is now 6
x--; // x is now 5
x += 10; // x is now 15
Comparison Operators
== // Equal to
!= // Not equal to
> // Greater than
< // Less than
>= // Greater than or equal
<= // Less than or equal
// Examples
5 == 5 // true
5 != 3 // true
10 > 5 // true
Logical Operators
&& // AND — both must be true
|| // OR — at least one true
! // NOT — reverses boolean
int age = 25;
boolean hasID = true;
boolean canDrink = (age >= 21) && hasID; // true
// Ternary operator (shorthand if/else)
String msg = (age >= 18) ? "Adult" : "Minor"; // "Adult"
Math Class
Math.max(10, 20); // 20
Math.min(10, 20); // 10
Math.abs(-5); // 5
Math.sqrt(16); // 4.0
Math.pow(2, 3); // 8.0
Math.round(3.7); // 4
Math.random(); // Random 0.0 to 1.0
✅ Quick Quiz
❓ What is 10 / 3 in Java (both ints)?
❓ What does && mean?
❓ What does the ternary operator do?