Type Casting & Operators

Widening (automatic): int to double. Narrowing (manual): double to int — you must cast: (int) 9.99 becomes 9.

Type Casting — converting between types

Widening (automatic): int to double. Narrowing (manual): double to int — you must cast: (int) 9.99 becomes 9.

Casting can lose data — 9.99 becomes 9 when cast to int.

Real-life example: Pouring a large bottle into a small cup — some water spills (data loss). Casting double to int drops the decimal part.

Widening and narrowing

int a = 10;
double b = a;        // automatic widening

double x = 9.99;
int y = (int) x;     // manual narrowing → 9
System.out.println(y);

Operators — arithmetic and assignment

+ - * / % for math. ++ and -- add or subtract 1. +=, -= combine assignment with operation.

Comparison: == != > < >= <=. Logical: && || ! for combining boolean conditions.

Real-life example: Operators are calculator buttons. + adds, == checks if two numbers are equal, && means both conditions must be true.

Arithmetic and logical operators

int a = 10, b = 3;
System.out.println(a + b);   // 13
System.out.println(a % b);   // 1 (remainder)

boolean ok = (a > 5) && (b < 10);
System.out.println(ok);      // true