Multiple inputs on one line

c++ input cin
Joshua picture Joshua · Sep 15, 2011 · Viewed 136.9k times · Source

I have looked to no avail, and I'm afraid that it might be such a simple question that nobody dares ask it.

Can one input multiple things from standard input in one line? I mean this:

float a, b;
char c;

// It is safe to assume a, b, c will be in float, float, char form?
cin >> a >> b >> c;

Answer

Robᵩ picture Robᵩ · Sep 15, 2011

Yes, you can input multiple items from cin, using exactly the syntax you describe. The result is essentially identical to:

cin >> a;
cin >> b;
cin >> c;

This is due to a technique called "operator chaining".

Each call to operator>>(istream&, T) (where T is some arbitrary type) returns a reference to its first argument. So cin >> a returns cin, which can be used as (cin>>a)>>b and so forth.

Note that each call to operator>>(istream&, T) first consumes all whitespace characters, then as many characters as is required to satisfy the input operation, up to (but not including) the first next whitespace character, invalid character, or EOF.

Related questions

Why would we call cin.clear() and cin.ignore() after reading input?

Google Code University's C++ tutorial used to have this code: // Description: Illustrate the use of cin to get input // and how to recover from errors. #include <iostream> using namespace std; int main() { int input_var = 0; // Enter the do …

Read More
cin and getline skipping input

earlier i posted a question about cin skipping input, and I got results to flush, and use istringstream, but now I tried every possible solution but none of them work. here is my code: void createNewCustomer () { string name, address; cout &…

Read More
C++: how do I check if the cin buffer is empty?

How do you check to see if the user didn't input anything at a cin command and simply pressed enter?

Read More