Overview of Decision Sequences and Boolean Logic

 

Branching

 

To be successful you should follow these tasks weekly

 

    read the overview page in each assigned module

    read the lecture notes posted in modules

    participate in the discussion forums

    review the supplement documents and example code posted in the modules

    attempt the practice exercise in the module

    complete the module assignments

    complete the module quiz

 

Important Reminder

The correct process for responding to discussions is to first post your own reply to the discussion topic.  Other participant’s replies will not be visible until you post your first individual reply.  Second, you must post a brief reply to at least two other students’ replies. This along with a relevant individual reply will give you full credit in discussion assignments.

 To provide additional flexibility for students that do not have their own personal computer resources, I am extending the deadline for some assignment submissions

 

Highlights This Week

This week we close out Chapter 2 on basic arithmetic operations in Python,

In chapter 3 we will examine the logical structure of algorithms and focus on implementing conditional execution in Python code. This has a variety of names in Computer Science and Computer Technology.  In some circles it is call branching and in others it is called selection sequences.   In Python this centers on three programming statements.  (If, if else, if-elif-else  ).  This chapter will examine these three statements and the fundamental concepts of selection sequences.

The chapter begins with a look at relational operations that compare values to yield true or false results.  These relational operations are referred to as logical expressions. Logical expressions use comparative operators to compare the values of data in computer memory. You will need to use these comparison operators in order to perform comparative operations.  There are six comparative operators available in most software that provides the capability to write logical expressions.  The six comparative operators that most software applications provide are; greater than, less than, equal to, not equal to, less than or equal to and greater than or equal to.    The chapter also examines logical operations that combine values in Boolean expressions to make complex expressions. The logical operators discussed are the (and, or, not) logical operators.  Additionally, this chapter examines the nature of algorithms and their structure.  The concept of a Turing machine and its importance in the history of computer science and math is briefly examined. The remainder of the chapter focusses on looking at branching in Java.  The following week the class examines repetition sequences in the next chapter.

The chapter describes the nature of Selection Sequences. Selection sequences are categorized into three main types; Binary Bypasses, Binary Choices and Multiple Choices.   In a Binary Bypass, a sequences of statements are executing or they are not.  In a Binary Choice, one of two sets of statements are executed, but not both.  In a multiple choice selection, there are several sets of statements that may be executed. In Java, the Binary Bypass is implemented using if statements.  A Binary Choice is implemented using (if else) statements.   Multiple branching can also be implemented using a sequence of Binary Choices.