Multiple inputs on one line

Question

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;

Solution 1

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.

Solution 2

Yes, you can.

From cplusplus.com:

Because these functions are operator overloading functions, the usual way in which they are called is:

   strm >> variable;

Where strm is the identifier of a istream object and variable is an object of any type supported as right parameter. It is also possible to call a succession of extraction operations as:

   strm >> variable1 >> variable2 >> variable3; //...

which is the same as performing successive extractions from the same object strm.

Just replace strm with cin.

Comments

[Joshua]

Thank you. I was thinking so, but I couldn't really test it where I am, and I was itching for knowledge.

[Joshua]

I was aware of the leading whitespace thing, but not the rest. Neat!

[K-ballo]

Note that whitespace characters will only be consumed if the skipws flag is set.