问题
Possible Duplicate:
What does the word “literal” mean?
Often when reading literature about C++, I encounter the word "literal". It is a bit unclear to me what exactly this term means in C++.
回答1:
A literal is some data that's presented directly in the code, rather than indirectly through a variable or function call.
Here are some examples, one per line:
42
128
3.1415
'a'
"hello world"
The data constituting a literal cannot be modified by a program, but it may be copied into a variable for further use:
int a = 42; // creates variable `a` with the same value as the literal `42`
This concept is by no means unique to C++.
The term "literal" comes from the fact that you've written data literally into your program, i.e. exactly as written, not "hidden" behind a variable name.
回答2:
Wikipedia gives you quickly this about literals.
In your C or C++ source code, Things like 1234, nullptr (in recent C++), "abcd" are literals.
来源：https://stackoverflow.com/questions/14111329/what-is-a-literal-in-c