Why Are String Literals Lvalues in C/C ?

Unique Properties of String Literals in C/C

In C and C , string literals are distinguished from other literals by their lvalue nature, a property that raises questions about the underlying rationale. According to the C 03 and C99 standards, string literals are lvalues, while all other literals are rvalues.

Root Cause: Array Type

The key to understanding this distinction lies in the internal representation of string literals. Unlike other literals, string literals are stored as arrays of characters. In C, arrays are always lvalues, which means string literals are inherently lvalues due to their array type.

Design Considerations

One might argue that an alternative approach would have been to treat string literals as pointers to the character array, making them rvalues. However, this design choice would have reduced their practicality. For instance, applying the sizeof operator to a string literal would not have returned the size of the character array, a common operation in C programming.

Broader Context

The distinction between lvalues and rvalues is not unique to string literals. With the introduction of compound literals in C99, other lvalues were added to the language. This suggests that making string literals lvalues is less of an exception and more in line with the evolving design of C/C .

Hardware Considerations

It is important to note that the rationale behind this design decision may also be influenced by hardware architecture. However, a detailed discussion of how hardware factors into the equation would go beyond the scope of programming language design and is often not covered in C/C documentation.

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