Chapter 2 Beginning ProblemSolving Concepts for the Computer

Overview � Constants and Variables � Data Types � How the Computer Stores Data � Functions � Operators � Expressions and Equations. Bullet, etc 02

Objectives 1. 2. 3. Differentiate between variables, constants. Differentiate between character, numeric, and logical data types. Identify operators, operands, resultants. 03

Objectives 5. 6. 7. Identify, use functions Identify, use operators according to placement in hierarchy chart. Set up, evaluate expressions and equations using variables, constants, operators, and the hierarchy of operations. 04

Figure 2. 1 Important Concepts to Learn 05

Table 2. 1 Constants and Variables on the Computer 06

Table 2. 1 Constants and Variables on the Computer 07

Rules for Naming and Using Variables 1. 2. 3. 4. Name a variable according to what it represents. Do not use spaces. Start a variable name with a letter. Do not use a dash or any other symbol that is used as a mathematical operator. 08

Rules for Naming and Using Variables 5. 6. 7. Consistent usage of variable name. Consistent use of upper, lowercase characters in variable names Use naming convention specified by your company 09

Table 2. 2 Incorrect Variable Names 010

Figure 2. 2 Processing Data—How a Computer Balances a Checkbook 011

Table 2. 3 Data Types and Their Data Sets 012

Table 2. 4 Examples of Data Types 013

Table 2. 4 Examples of Data Types 014

Table 2. 5 Functions 015

Table 2. 5 Functions 016

Table 2. 5 Functions 017

Table 2. 5 Functions 018

Table 2. 6 Operators and Their Computer Symbols 019

Table 2. 6 Operators and Their Computer Symbols 020

Table 2. 7 Definitions of the Logical Operators 021

Table 2. 7 Definitions of the Logical Operators 022

Table 2. 7 Definitions of the Logical Operators 023

Table 2. 8 Hierarchy of Operations 024

Table 2. 8 Hierarchy of Operations 025

Table 2. 9 Expressions and Equations 026

Evaluating a Mathematical Expression 027

Evaluating a Relational Expression 028

Evaluating a Logical Expression 029

Evaluating an Equation That Uses Both Relational and Logical Operators 030

Developing a Table of All Possible Resultants of a Logical Expression unknown—A. � Two combinations: A can be either True or � One False. 031

Developing a Table of All Possible Resultants of a Logical Expression unknowns—A and B. � Four combinations: B can be either True or False for each value of A. . � Two 032