Why Does SomeFunction().c_str() Return Garbage Data While str_copy = SomeFunction(); str_copy.c_str(); Works Correctly?

Understanding the Function of c_str() for Strings Returned by Functions

When your function SomeFunction() returns a string, it may appear that calling c_str() on the returned string will convert it successfully to a const character pointer. However, in certain scenarios, you may encounter unexpected behavior.

As the provided code demonstrates, calling c_str() directly on SomeFunction() results in a const character pointer (charArray) referencing garbage data, while assigning the returned string to another string (str) and then calling c_str() on it gives you the intended behavior.

Why this occurs:

SomeFunction().c_str() provides a pointer to a temporary variable (the str variable inside SomeFunction()) that exists only within the function's scope. After the function returns, that variable is destroyed, and the pointer (charArray) becomes a dangling pointer.

In contrast, when you use str_copy = SomeFunction(), a copy of the returned string is made. This new string exists outside the function, and when you call c_str() on it, the pointer it returns points to valid data, ensuring the correct conversion.

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