The term flow of control refers to the order in which a program's statements are executed. Every programming language supports three control flow structures namely
The normal flow of control for all programs is sequential. In sequential structure, a sequence of program statements are executed one after another in the order in which they are placed. Both selection and repetition statements allow the programmer to alter the normal sequential Mow of control. The selective structure allows the usual sequential order of execution to be modified. It consists of a test for a condition followed by alternative paths that the program can follow. The program selects one of the alternate paths depending upon the result of the test for condition. The iterative structure provides the ability to go back and repeat a set of statements. Iterative structure is otherwise referred to as repetitive structure.