Why Does Directly Calling c_str() on a Function\'s String Return Garbage?

Understanding the Invalidity of c_str() Direct Invocation on Function Returning String

When dealing with functions that return strings, invoking c_str() directly on the returned function can lead to unexpected outcomes. In this specific instance, c_str() attempts to convert the returned string into a const char, but the resulting const char stores garbage value instead.

The fundamental issue lies in the temporary nature of the string returned by SomeFunction(). c_str() yields a pointer to this temporary string, which is invalid once the function execution concludes. This leads to the garbage value being stored in the const char*.

To rectify this issue, it's crucial to understand the difference between references and pointers. While references extend the lifetime of their referenced objects, temporary object pointers like c_str() do not. Hence, the dangling pointer problem arises with charArray.

In contrast, when you declare a new string variable (str_copy) and assign it the return value of SomeFunction(), you create a copy of the temporary string. This copy remains valid, and invoking c_str() on str_copy returns a valid const char* pointing to the string's contents.

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