THINK++ — Engineering Visualized

03 // I/O Streams

Input & Output

C++ uses stream objects for I/O operations. The iostream header provides cin and cout as the primary channels for reading input and displaying output.

cout

Output Stream

Sends data to the console screen

operator <<

cin

Input Stream

Reads data from the keyboard

operator >>

cerr

Error Stream

Outputs unbuffered error messages

operator <<

clog

Log Stream

Outputs buffered log messages

operator <<

Basic Output

cout << "Hello, World!" << endl;

Variable Output

int x = 42;
cout << "Value: " << x << endl;

Basic Input

int age;
cin >> age;

Multiple Inputs

int a, b;
cin >> a >> b;

endl vs \\n

Both create a newline, but endl also flushes the buffer. In competitive programming, use \n for faster output.

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Input Output

Input Output

Input & Output

endl vs \\n

Input & Output

endl vs \\n