C++ Literals
Invariant program elements are called "literals" or "constants." The terms "literal" and "constant" are used interchangeably here. Literals fall into four major categories: integer, character, floating-point, and string literals.
A literal may be any of the following:
integer-constant
character-constant
floating-constant
string-literal
Examples
157 // integer constant
0xFE // integer constant
'c' // character constant
0.2 // floating constant
0.2E-01 // floating constant
"dog" // string literal
For more examples, see the following sections, referenced above.