Primitive types and conversion

Java has eight primitive types: byte, short, int, long, float, double, char, and boolean. Numeric types differ in range and precision; boolean represents true/false and is not numeric.

Widening converts a type to a type with a broader range, usually implicitly:

int count = 25;
double value = count; // 25.0, no narrowing loss

Narrowing converts to a smaller or less precise type and requires a cast:

double price = 19.95;
int whole = (int) price; // 19: fractional part lost
int n = 130;
byte b = (byte) n; // wraps to -126 for 8-bit signed byte

A cast permits the conversion; it does not guarantee that the original value is preserved. Use appropriate types and validate ranges.