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

• The second << has cout << " Hello World!" as its left operand and endl as its right operand.

• Remember the value of its left operand was cout, so this operand simply writes an additional end of line character to standard out and returns the value of cout.

• For now, you can simply think of the side effects and what they can do for you.

• The effect of an operator depends on the types of its operands.