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A literal is a primary expression. Its type depends on its form (2.13). A string literal is an lvalue; all other literals are rvalues.
Strings in C are arrays of char elements, so we can't really return a string - we must return a pointer to the first element of the string. All forms are perfectly valid. Note the use of const , because from the function I'm returning a string literal, a string defined in double quotes, which is a constant.
In C++, an ordinary string literal has type 'array of n const char'. For example, The type of the string literal "Hello" is "array of 6 const char". It can, however, be converted to a const char* by array-to-pointer conversion.
A "string literal" is a sequence of characters from the source character set enclosed in double quotation marks (" "). String literals are used to represent a sequence of characters which, taken together, form a null-terminated string.
The C standard recognizes the original terms stood for left and right as in L = R; however, it says to think of lvalue as locator value, which roughly means you can get the address of an object and therefore that object has a location. (See 6.3.2.1 in C99.)
By the same token, the standard has abandoned the term rvalue, and just uses "the value of an expression", which is practically everything, including literals such as ints, chars, floats, etc. Additionally, anything you can do with an rvalue can be done with an lvalue too, so you can think of all lvalues as being rvalues.
There are two kinds of expressions in C: 1. lvalue: An expression that is an lvalue may appear as either the left-hand or right-hand side of an assignment. 2. rvalue: An expression that is an rvalue may appear on the right- but not left-hand side of an assignment. Variables are lvalues and so may appear on the left-hand side of an assignment. Numeric literals are rvalues and so may not be assigned and cannot appear on the left-hand side. Following is a valid statement: int g = 20; But following is not a valid statement and would generate compile-time error: 10=20;
there's a definition for C++ from Microsoft. By this definition, a literal string, say "hello world", is lvalue, because it's const and not temporary. Actually it persists across your application's lifetime.
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