There are three important control flow statements to alter the control flow depending on the state.
1. In sequential control flow, a sequence of statements are executed one after another in the same order as they are written.
2. In alternative control flow, a condition of the state is tested, and if the condition is true, one statement is executed; if the condition is false, an alternative statement is executed.
3. In iterative control flow, a condition of the state is tested, and if the condition is true, a statement is executed. The two steps of testing the condition and executing the statement are repeated until the condition becomes false.