Presentation is loading. Please wait.

Presentation is loading. Please wait.

Fall 2007ACS-1805 Ron McFadyen1 Boolean functions & expressions A boolean function is one that returns true or false The guidelines for class-level methods.

Published by Modified over 9 years ago

Similar presentations

Presentation on theme: "Fall 2007ACS-1805 Ron McFadyen1 Boolean functions & expressions A boolean function is one that returns true or false The guidelines for class-level methods."— Presentation transcript:

1 Fall 2007ACS-1805 Ron McFadyen1 Boolean functions & expressions A boolean function is one that returns true or false The guidelines for class-level methods also apply to class- level functions: No references to other objects. No references to world-level functions you have written, but built-in world-level functions are fine to use

2 Fall 2007ACS-1805 Ron McFadyen2 Boolean expressions Expressions like a==b test two operands and return a value of true or false. Boolean expressions are used in while, if expressions, … A boolean function has returns like: Boolean operators not, and, or can be expressed in tabular form a!=b means “a not equal to b”

3 Fall 2007ACS-1805 Ron McFadyen3 Boolean expressions These are simple boolean expressions that are either true of false What is the phrase: possiblePhilosopher = who ?

4 Fall 2007ACS-1805 Ron McFadyen4 Boolean expressions Not operator anot a truefalse true

5 Fall 2007ACS-1805 Ron McFadyen5 Boolean expressions And operator ba and b true false a true false

6 Fall 2007ACS-1805 Ron McFadyen6 Boolean expressions Or operator ba or b true falsetrue a false … In alice, we compose boolean expressions that are of a nested form:

7 Fall 2007ACS-1805 Ron McFadyen7 Boolean expressions The text has a couple of examples on page 167: 1. either (both(who==homer) and (who.color==blue)) or (who.color==black) or both Consider: And then we develop: How is this interpreted, how is it developed?

8 Fall 2007ACS-1805 Ron McFadyen8 Boolean expressions The text has a couple of examples on page 167: 2. both(who==homer) and (either who.color==blue or who.color==black or both) Consider: And then we develop: How is this interpreted, how is it developed?

9 Fall 2007ACS-1805 Ron McFadyen9 Boolean expressions The text has a couple of examples on page 167: 1. either (both(who==homer) and (who.color==blue)) or (who.color==black) or both 2. both(who==homer) and (either who.color==blue or who.color==black or both) Are they the same? Are they different?

10 Fall 2007ACS-1805 Ron McFadyen10 Ch6 ends with Random Functions There are two random functions in alice: 1.Choose true …. Returns a boolean value 2.Random number Returns a number as you prescribe

Download ppt "Fall 2007ACS-1805 Ron McFadyen1 Boolean functions & expressions A boolean function is one that returns true or false The guidelines for class-level methods."

Similar presentations

The IF function Bernard Liengme. Objectives To know how to: Construct a condition using the comparison operators =, >=, >, ; Construct a formula using.

The IF function Bernard Liengme. Objectives To know how to: Construct a condition using the comparison operators =, >=, >, ; Construct a formula using.
© 2007 Lawrenceville Press Slide 1 Chapter 5 The if Statement  Conditional control structure, also called a decision structure  Executes a set of statements.

© 2007 Lawrenceville Press Slide 1 Chapter 5 The if Statement  Conditional control structure, also called a decision structure  Executes a set of statements.
3. S/E with Control Structures 3.1 Relational Operators and Expressions 3.2 If and if-else Statements 3.3 The Type Double 3.4 Program Design with the While.

3. S/E with Control Structures 3.1 Relational Operators and Expressions 3.2 If and if-else Statements 3.3 The Type Double 3.4 Program Design with the While.
Decision Structures Chapter 4. Chapter 4 Objectives To understand: o What values can be stored in a Boolean variable o What sequence structures are and.

Decision Structures Chapter 4. Chapter 4 Objectives To understand: o What values can be stored in a Boolean variable o What sequence structures are and.
Fall 2007ACS-1805 Ron McFadyen1 Ch 7 Loops Alice has two control structures for controlling the repeated execution of statements Loop While.

Fall 2007ACS-1805 Ron McFadyen1 Ch 7 Loops Alice has two control structures for controlling the repeated execution of statements Loop While.
Fall 2009ACS-1805 Ron McFadyen1 Ch 7 Loops Alice has two control structures for controlling the repeated execution of statements Loop While.

Fall 2009ACS-1805 Ron McFadyen1 Ch 7 Loops Alice has two control structures for controlling the repeated execution of statements Loop While.
Fall 2009ACS-3913 Ron McFadyen Composite Pattern Problem: How do we treat a composition structure of objects the same way as a non-composite object? Arises.

Fall 2009ACS-3913 Ron McFadyen Composite Pattern Problem: How do we treat a composition structure of objects the same way as a non-composite object? Arises.
If Statements & Relational Operators Programming.

If Statements & Relational Operators Programming.
Fall 2009ACS-1805 Ron McFadyen1 Functions A function is a collection of statement, similar to a method, but a function is defined to return a value to.

Fall 2009ACS-1805 Ron McFadyen1 Functions A function is a collection of statement, similar to a method, but a function is defined to return a value to.
A Quick Look at Quantified Statements. Why are Quantified Statements Important? The logical structure of quantified statements provides a basis for the.

A Quick Look at Quantified Statements. Why are Quantified Statements Important? The logical structure of quantified statements provides a basis for the.
Week 10 Recap CSE 115 Spring 2007. For-each loop When we have a collection and want to do something to all elements of that collection we use the for-each.

Week 10 Recap CSE 115 Spring For-each loop When we have a collection and want to do something to all elements of that collection we use the for-each.
Fall 2007ACS-1805 Ron McFadyen1 Functions and if-else A function is a collection of statement, similar to a method, but a function is defined to return.

Fall 2007ACS-1805 Ron McFadyen1 Functions and if-else A function is a collection of statement, similar to a method, but a function is defined to return.
2-1 Making Decisions Sample assignment statements PayAmount = Hours * Rate PayAmount = 40*Rate + (Hours – 40)*Rate*1.5.

2-1 Making Decisions Sample assignment statements PayAmount = Hours * Rate PayAmount = 40*Rate + (Hours – 40)*Rate*1.5.
Fall 2008ACS-1805 Ron McFadyen1 Ch 8 Recursion Recursion occurs when a method (or function) calls itself.

Fall 2008ACS-1805 Ron McFadyen1 Ch 8 Recursion Recursion occurs when a method (or function) calls itself.
Fall 2007ACS-1805 Ron McFadyen1 Programming Concepts Chapter 4 introduces more advanced OO programming techniques. Construction of a programs usually requires:

Fall 2007ACS-1805 Ron McFadyen1 Programming Concepts Chapter 4 introduces more advanced OO programming techniques. Construction of a programs usually requires:
1 Fall 2008ACS-1805 Techniques for designing code Storyboards Text (aka pseudocode) Diagrams Flowcharts (a procedural technique) Text presents one of these.

1 Fall 2008ACS-1805 Techniques for designing code Storyboards Text (aka pseudocode) Diagrams Flowcharts (a procedural technique) Text presents one of these.
Fall 2007ACS-1805 Ron McFadyen1 Chapter 7 Repetition.

Fall 2007ACS-1805 Ron McFadyen1 Chapter 7 Repetition.
Fall 2007ACS-1805 Ron McFadyen1 Ch 7 Loops Alice has two control structures for controlling the repeated execution of statements Loop While.

Fall 2007ACS-1805 Ron McFadyen1 Ch 7 Loops Alice has two control structures for controlling the repeated execution of statements Loop While.
Assignment 2 Sample problems. Consider the following expression: ((False and not True) or False or (True and not True)) True False.

Assignment 2 Sample problems. Consider the following expression: ((False and not True) or False or (True and not True)) True False.
Fall 2007ACS-1805 Ron McFadyen1 Chapter 3 Programming - Putting Together the Pieces.

Fall 2007ACS-1805 Ron McFadyen1 Chapter 3 Programming - Putting Together the Pieces.

Similar presentations

Ads by Google