Std::cin
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Syntax
extern istream cin;
Description
Standard input stream
Object of class istream that represents the standard input stream oriented to narrow characters (of type char). It corresponds to the C stream stdin.
The standard input stream is a source of characters determined by the environment. It is generally assumed to be input from an external source, such as the keyboard or a file.
As an object of class istream, characters can be retrieved either as formatted data using the extraction operator (operator>>) or as unformatted data, using member functions such as read.
The object is declared in header <iostream> with external linkage and static duration: it lasts the entire duration of the program.
Example
| Source | Run |
|---|---|
#include <iostream>
#include <string>
using namespace std;
int main()
{
int age(0), nkids(0);
string name("");
cout << "What's your name? ";
getline(cin, name);
cout << "How old are you? ";
cin >> age;
cout << "How may kids do you have? ";
cin >> nkids;
cout << "Hello " << name << ". You are " << age << " years old and have " << nkids << " kids." << endl;
return 0;
}
|
$ ./main What's your name? Alice Shaw How old are you? 38 How may kids do you have? 3 Hello Alice Shaw. You are 38 years old and have 3 kids. |