Why Can't I Directly Assign Arrays in C ?

Why Arrays Are Unassignable in C

In C , arrays cannot be assigned to other arrays directly. This behavior may seem strange, but it is due to the language's heritage from C.

The error message "Error C2106: '=' : left operand must be l-value" indicates that the left operand (in this case, values) must be an l-value, which is a modifiable object that can be assigned to. However, arrays are not considered l-values in C .

Reasons for Unassignable Arrays

C arrays are not assignable for several reasons:

• Legacy Compatibility: Arrays in C are backward compatible with C arrays, which were implemented as pointers and could not be assigned directly.
• Array Size: Arrays have a fixed size once declared. Assigning one array to another would require changing the size of the array, which is not allowed in C .

Alternative Solutions

To work with arrays in C , there are several alternative solutions:

• std::array and std::vector: C offers modern containers like std::array and std::vector. These containers allow for assignment and resizing, respectively.
• Loop-Based Copying: As a last resort, you can manually copy elements between arrays using loops.

Example:

#include <algorithm>

// Original arrays
int numbers[5] = {1, 2, 3};
int values[5] = {};

// Copying elements using std::copy
std::copy(numbers, numbers + 5, values);

Alternatively, using std::array:

#include <array>

// Modern arrays
std::array<int, 5> numbers = {1, 2, 3};
std::array<int, 5> values = {};

// Assignment
values = numbers;

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