operators-and-expressions.md

Operators And Expressions

Arithmetic Operators

• + addition
• - subtraction
• * multiplication
• / division
• % remainder

Example:

int a = 5;
int b = 2;

System.out.println(a + b); // 7
System.out.println(a - b); // 3
System.out.println(a * b); // 10
System.out.println(a / b); // 2
System.out.println(a % b); // 1

String Concatenation

• When + is used with strings, Java joins values as text.

Example:

System.out.println("Hello" + "World"); // HelloWorld
System.out.println("2" + "3");         // 23
System.out.println(2 + 3 + "2" + 2);   // 522

Comparison Operators

• == equal to
• != not equal to
• > greater than
• < less than
• >= greater than or equal to
• <= less than or equal to

Example:

System.out.println(10 > 5);  // true
System.out.println(10 == 5); // false

Logical Operators

• && logical AND
• || logical OR
• ! logical NOT

Example:

System.out.println(10 + 5 > 4 && 5 + 7 > 10); // true
System.out.println(10 + 5 < 4 && 5 + 7 > 10); // false

Short-Circuit Evaluation

• In &&, if the left side is false, Java does not evaluate the right side.
• In ||, if the left side is true, Java does not evaluate the right side.

Example:

System.out.println(10 + 5 < 4 && 5 / 0 > 10);

This does not throw an error because the first condition is already false.

Unary Operators

• x++ is post-increment
• ++x is pre-increment
• x-- is post-decrement
• --x is pre-decrement

Example:

int x = 5;
System.out.println(x++); // 5
System.out.println(x);   // 6
System.out.println(++x); // 7

Ternary Operator

• A short form of if-else

Syntax:

condition ? valueIfTrue : valueIfFalse;

Example:

int marks = 64;
String status = (marks >= 33) ? "Pass" : "Fail";