primitives

• The range of short primitive type is -32768 to 32767.
• Java does not allow casts between boolean values and any numeric types.
• Assigning double to a float requires an explicit cast.
• The width in bits of float primitive type in Java is 32.
• byte 8 bits, short 16 bits, int 32 bits, float 32 bits, long 64 bits, double 64 bits
• 2.23 is double
• 2.23f is float
• byte range is from -128 to 127
• Setting a value to a long for numbers exceeding int limit is like this (L suffix):
  • long foo = 3333333333L;
• Use '0' prefix for octal digits, for example 010 = 8
• Use '0X' or '0x' prefix for hexadecimal digits, for example 0x10 = 16
• Use '0B' or '0b' prefix for binary digits, for example 0b10 = 2
• From Java 7, you can have underscores to make digits easy to read for example "int a =1_000_000" or "float b=12_544.10", for float and double the "_" should not be around or after "." sign.
• In Java there is no connection between false and 0 or true and 1

Keyword	Type	Example
boolean	true or false	true
byte	8-bit integral value	123
short	16-bit integral	123
int	32-bit integral	123
long	64-bit integral	123
float	32-bit floating-point value	123.45f
double	64-bit floating-point value	123.45
char	16-bit Unicode value	'a'