Do return by address or reference is safe?

Most of the time, return by value will be sufficient for your needs. It’s also the most flexible and safest way to return information to the caller. However, return by reference or address can also be useful, particularly when working with dynamically allocated classes or structs.

Which function returns the address of a local variable?

A function returns the address of a stack variable, which will cause unintended program behavior, typically in the form of a crash. Because local variables are allocated on the stack, when a program returns a pointer to a local variable, it is returning a stack address.

What does it mean to return a reference?

When a function returns a reference, it returns an implicit pointer to its return value. This way, a function can be used on the left side of an assignment statement. For example, consider this simple program −

Can I return a local variable C++?

But there is a way to access the local variables of a function using pointers, by creating another pointer variable that points to the variable to be returned and returning the pointer variable itself.

Can we return address of a local variable in C?

Pointers in C programming language is a variable which is used to store the memory address of another variable. But it is not recommended to return the address of a local variable outside the function as it goes out of scope after function returns.

How does a function return values?

A function defined with a return type must include an expression containing the value to be returned. In this example, the return statement initializes a variable of the returned type. The variable answer is initialized with the int value 30. The type of the returned expression is checked against the returned type.

Which is better pass-by-value or reference?

Pass-by-references is more efficient than pass-by-value, because it does not copy the arguments. The formal parameter is an alias for the argument. Use pass-by-reference if you want to modify the argument value in the calling function. Otherwise, use pass-by-value to pass arguments.

How do you decide whether to return by reference or by value from an overloaded operator?

The rule you should use is:

1. if the built-in operator returns an rvalue then your overload should return a reference.
2. if the built-in returns an lvalue then your overload should return a value.

When should I Be careful when returning an address from a variable?

You should always be careful when returning addresses to local variables; as a rule, you could say that you never should. static variables are a whole different case though, which is being discussed in this thread.

Why does Nevernever return a reference to a variable?

Never return a reference to a local variable or some such, because it won’t be there to be referenced. You can return a reference to something independent of the function, which you don’t expect the calling function to take the responsibility for deleting. This is the case for the typical operator [] function.

Is it safe to call a function from a local variable?

A local variable is memory on the stack, that memory is not automatically invalidated when you go out of scope. From a Function deeper nested (higher on the stack in memory), its perfectly safe to access this memory. Once the Function returns and ends though, things get dangerous.

Is it bad to return a reference from a function?

In general, returning a reference is perfectly normal and happens all the time. If you mean: int& getInt() { int i; return i; // DON’T DO THIS. That is all sorts of evil. The stack-allocated iwill go away and you are referring to nothing.