In C++, the << and the >> are overloaded to perform I/O operations. When used in an expression in which the left operand is a stream, the >> is an input operator and the << is an output operator. In the language of C++, the >> is called an extractor because it extracts data from the input stream. The << is called an inserter because it inserts data into the output stream. The general forms of these operators are shown here:
input-stream >> variable; output-stream << expression
For example, the following fragment inputs two integer variables:
int i, j; cin >> i >> j;
The following statement displays “This is a test 10 20”:
cout << "This is a test " << 10 << << ' ' << 4*5;
The I/O operators are not supported by C.