Chapter 5 Flow Control - Part 1
Executing a sequence of of Java statements is useful, especially when we have a deterministic calculation to perform. But it is often the case that we want to perform different calculations depending on the outcome of some expression, the response of a user, or another condition in our program. For example, we might use a
Scanner class to ask the user what they would like the program to do on their behalf. We need to read the input and execute only the relevant part of your program.
Branching is the term used when a program executes different parts of a program based on the outcome of some condition. If running a program is like walking down a road, branching is like coming to a fork in that road and deciding which way to go. if-statements are the most common way to branch execution of a program, and often it is both relational expressions 2.10 and logical expressions 2.11 that help us make the decision about which way to go.
Iteration is the term used when a program may execute the same block of code multiple times while some condition continues to be true. Once again, relational expressions 2.10 and logical expressions 2.11 help us decide whether or not to continue executing the code block, or to stop and pick up execution after the block.
In this chapter we will introduce the first forms of branching and iteration in Java. In Chapter 6 we will explore other ways to perform similar forms of control over your program’s flow.
