Quiz 1

1
Quiz 1

• Exam 1 Next Week

2
Nested if Statements

• if (myGrade gt 80)
• if (myGrade gt 90)
• cout ltlt You have an A! ltlt endl
• else
• cout ltlt You have a B! ltlt endl
• else
• cout ltlt Well give you a C. ltlt endl

3
if/else (Cascaded)

• Sequence of if/else Statements
• Example
• if (myGrade gt 90)
• cout ltlt A! ltlt endl
• else
• if (myGrade gt 80)
• cout ltlt B! ltlt endl
• else
• if (myGrade gt 70)
• cout ltlt C! ltlt endl
• else
• cout ltlt Oh-oh! ltlt endl

4
Boolean Type

• A Boolean Value Is One of Either True or
  False
• In C, Type bool
• Example
• bool done false
• . . .
• if (currentLetter Z)
• done true
• else
• done false
• if (done)
• return(0)
• . . .
• if/else Conditionals Must Evaluate to True or
  False, and Are Therefore Called Boolean
  Expressions
• In C, Any Non-Zero Value Is Considered True
  Any Expression Evaluating to Zero Is Considered
  False

5
Logical Operators

• A Logical Operator Is One Used to Further Specify
  True or False in an Expression
• Connects Two or More Expressions Together
• Is Logical AND
• Is Logical OR
• Both Operands Must Be True for Entire
  Expression to Be True
• Only One (or Both) of the Operands Must Be
  True for Entire Expression to Be True

6
Logical Operators

• if (numStudents gt MIN numStudents lt MAX)
• classRun true
• if (numStudents gt MAX numInstructors 0)
• classRun false

7
Operator Precedence

• ()
• ! (not)
• , /,
• , -
• lt, lt, gt, gt (Relational Operators)
• , ! (Equality Operators)
• (Logical AND)
• (Logical OR)
• (ASSIGNMENT)

8
Order of Operations

• Precedence Level of Importance of Operations
• Multiplicative Operators Have Higher Precedence
  than Additive Operators
• , /, Higher
• , - Lower
• Associativity Order of Operation for Equal Level
  Precedence
• Most Operators Have Left-to-Right Associativity
• Use Parentheses to Force Differing Precedence of
  Operations

9
Multiple Logical Operators

• if ( num1 gt MAX num2 0 num3 0)
• cout ltlt num1 is MAX or something is 0
• cout ltlt I think.. ltlt endl

10
Switch Statements

• Also Called Switch/Case Statement
• Just Case in Other Languages
• Selects Among Several Different Actions
• Can Only Select from Integer or Character
• If an Integer Value Is Matched, Statements under
  Control of that Case Block Are Executed

11

Switch/Case Example

• const double BASERATE 104.50
• double rate
• int numPassengers
• cout ltlt Enter Passengers
• cin gtgt numPassengers
• switch(numPassengers)
• case 2
• rate BASERATE 0.80
• break
• case 4
• rate BASERATE 0.75
• break
• case 5
• rate BASERATE 0.55
• break
• default
• rate BASERATE
• break

12
Switch Case Example

• char menuItem
• cout ltlt "Enter Menu Selection "
• cin gtgt menuItem
• switch(menuItem)
• case 'O'
• case o'
• / code to do ordering goes here/
• break
• case 'C'
• case c'
• / code to do checkout goes here/
• break
• default
• cout ltlt Unknown option ltlt endl
• break

13
Announcements

• Exam 1 Next Week in Lecture
• Everything through Lab 4
• 50 minutes
• 10 of Total Grade
• Covers Everything through Lecture this Week
• Quiz 1 Topics (terminology, variables, constants,
  basics)
• if-then-else
• Compound statements
• Relational operators
• Logical operators
• Switch/Case Statements