In C++ what is the difference between return by value and return by reference in the function?

Question

abc abc 351

Hi,

When we need to use return by value and return by reference in the function?

Thanks.

David Lowndes 4,726 Reputation points

2022-05-08T13:17:19.063+00:00

Have a look at this answer.
abc abc 351 Reputation points

2022-05-08T13:45:27.657+00:00

As per you suggested link, if we should not return reference of local variable in the function, then what is the use of returning reference , we can return the value itself. I could not understand , please help.
David Lowndes 4,726 Reputation points

2022-05-08T13:58:33.487+00:00

Remember that a reference is essentially just a pointer.
You should never return a reference to a local variable because it won't exist once the function has existed.
Returning a reference to something should only be done with careful consideration... the lifetime of what you're referencing needs to exceed the lifetime/use of the returned reference.
Generally it's only of use if copying the returned item is expensive, and you're sure your normal use of it won't break the lifetime issue.
abc abc 351 Reputation points

2022-05-08T14:06:22.7+00:00

Thanks for the explanation.

Your answer

David Lowndes 4,726 Reputation points

2022-05-08T13:17:19.063+00:00

Have a look at this answer.
abc abc 351 Reputation points

2022-05-08T13:45:27.657+00:00

As per you suggested link, if we should not return reference of local variable in the function, then what is the use of returning reference , we can return the value itself. I could not understand , please help.
David Lowndes 4,726 Reputation points

2022-05-08T13:58:33.487+00:00

Remember that a reference is essentially just a pointer.
You should never return a reference to a local variable because it won't exist once the function has existed.
Returning a reference to something should only be done with careful consideration... the lifetime of what you're referencing needs to exceed the lifetime/use of the returned reference.
Generally it's only of use if copying the returned item is expensive, and you're sure your normal use of it won't break the lifetime issue.
abc abc 351 Reputation points

2022-05-08T14:06:22.7+00:00

Thanks for the explanation.