This is an archived version of the course. Please find the latest version of the course on the main webpage.

Chapter 5: Breaking the flow

Altering the flow of loops

face Josiah Wang

In the good old days, programmers can arbitrarily ‘jump’ to different lines in code with a goto statement. This made it hard to read, understand and debug codes. This is generally considered a very bad thing nowadays, and most modern programming languages do not even provide this statement.

goto

In (strict) structured programming, there is a rule that each building block must have only one entry point and one exit point. This prevents programmers from ‘jumping’ around the code to anywhere they like.

Each building block has only one entry point and one exit point

However, sometimes it is easier to allow the programmer to break this rule to a certain extent. Such codes are sometimes easier to read than a strictly structured programming style.

In this chapter, we will explore the break statement that allows programmers to ‘interrupt’ the normal flow of a loop.