Writing to a Stream
The first statement in the body of
main executes an expression. In C++ an expression yields a result and is composed of one or more operands and (usually) an operator. The expressions in this statement use the output operator (the
« operator) to print a message on the standard output:
std::cout << "Enter two numbers:" << std::endl;
<< operator takes two operands: The left-hand operand must be an
ostream object; the right-hand operand is a value to print. The operator writes the given value on the given
ostream. The result of the output operator is its left-hand operand. That is, the result is the
ostream on which we wrote the given value.
Our output statement uses the
<< operator twice. Because the operator returns its ...