Question

int i,j;

std::string s;

std::cin>>i>>j>>s>>s>>i;

std::cout<<i<<" "<<j<<" "<<s<<" "<<i;

Question
Referring to the sample code above, what’s the displayed output if the input string given is: “5 10 Sample Word 15 20”?

The answer is

15 10 Word 15

I have the question is what’s the underline policy for cin to over write the existing values? Does the latter one simply overwrite the previous one? Is there any other situations?

I checked many books, but I didn’t find one which explain this.

Answer 1

std::cin >> i >> j >> s >> s >> i;

is equivalent to:

std::cin >> i;
std::cin >> j;
std::cin >> s;
std::cin >> s;  // overwrite previous s
std::cin >> i;  // overwrite previous i

Every time you read from cin to a variable, the old contents of that variable is overwritten.

So you are explicitly asking to overwrite s and i.