Character variable uses one byte of
memory, integer variable uses two bytes of memory whereas floating point
variable uses four bytes of memory.
Apart from variables we have constants
which never change their value during program execution. We can have character
constants, integer constants, floating point constants and string constants. Character
constant can be one or more characters enclosed in single quote, characters
enclosed in double quotes add extra null zero character in the memory that
denotes the end of the string. Integer constant can be of three types namely
Decimal constant (Base 10), Octal numbering system constant (Base 8) and
Hexadecimal numbering system constant (Base 16). Number of characters enclosed
in double quotes is a string constant. Quotes do not make part of the string.
Floating point constant holds decimal point numbers.
