Programming Languages - Number

Last Updated: 2021-11-19

Numerical Types

• byte: 8 bits, 0xFF
• short: 2 bytes, 16 bits, 0xFFFF
• int: 4 bytes, 32 bits, 0xFFFFFFFF
• long: 8 bytes, 64 bits,

int:

• 0xffffffff = -1
• 0x7fffffff = 2147483647
• 0x80000000 = -2147483648

Java

• Primitives Types: always have a value, cannot be null, default to false or 0, 0.0f, etc
  • boolean 1
  • byte 8
  • short 16
  • int 32
  • long 64: 1L
  • float 32: 1.0f
  • double 64: 1.0d
• Reference Types: can be null

Java Byte.toUnsignedInt(): promote byte x to int by adding 1s to the front

public static int toUnsignedInt(byte x) {
    return ((int) x) & 0xff;
}