Control Structure

Abstract

In our program to solve a quadratic equation in Section1.2, the user could enter values of a, b and c, which make:

$${b^2} - 4ac$$

negative. In such cases the program would fail, but there is nothing we can do to prevent this with the techniques we have learned so far. All of our programs have a very simple control structure. In fact control just passes from one statement to the next, with no alternative pathway through a program. Our next task is to introduce iteration and branching techniques, but before we consider these control structures a few preliminaries are needed; in particular, some new operators must be introduced. You can find the precedence and associativity of these operators in Appendix B.