Module3 Condition Statement

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Module3 Condition Statement
???????? ???????????Aphirak Jansang aphirak.j_at_ku.
ac.th http//www.cpe.ku.ac.th/aphirak Computer
Engineering Department Kasetsart University,
Bangkok THAILAND
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Outline

• C Overview Again
• Boolean Expression
• Condition Statement

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Simple C Structure
C Structure

• Namespace
• Class
• Main()

Variable Constant Location
Statements
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In Main() method
Main() method

• Variable Constant Declaration
• Statements

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C Variable Declaration
Variable Constant

• Syntax
• ltdata typegt ltnamegt
• Example
• We can also assign its initial value. E.g.,

int radius double area int a,b,c bool isokay
int k 200 bool done false
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C Constant Declaration
Variable Constant

• Syntax
• const ltdata typegt ltnamegt ltvaluegt
• Example

const int radius 15 const double
area1.5 const bool isokaytrue const string
movieStarWarIII
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C Program Example
Variable Constant
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In Main() method

• Variable Constant Declaration
• Statements

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C Statements
Statement

• Assignment Statement
• Ex. x 10
• Input Statement
• Ex. st Console.ReadLine()
• Output Statement
• Ex. Console.WriteLine(Hello World!)

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Simple C Program
C Overview
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C Program with Condition
C Overview
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Outline

• C Overview
• Boolean Expression
• Condition Statement

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Boolean Expression
Boolean Expression

• Operators

Math Notation C Notation Example Meaning
x y x is equal to y?
? ! x ! y x is not equal to y?
gt gt x gt y x is greater than y?
gt x gt y x is greater than or equal to y?
lt lt x lt y x is less than y?
lt x lt y x is less than or equal to y?
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Example Boolean Expression
Boolean Expression

• double x 4.0
• Expression Value
• x lt 5.0 ___________
• x gt 5.0 ___________
• x lt 5.0 ___________
• 5.0 x ___________
• x ! 5.0 ___________

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Example More Boolean Expression
Boolean Expression

• double n1 78.0
• double n2 80.0
• n1 lt n2 __________
• n1 gt n2 __________
• (n1 35) gt n2 __________
• Math.Abs(n1-n2) lt 0.001 __________
• n1 n2 __________
• n1 ! n2 __________

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Compound Boolean Expression
Boolean Expression

• Logical Operators
• - AND
• - OR
• ! NOT
• Example (a20 b12)
• (a gt 12) (a lt 20)
• (a 2 0) (b 2 0)

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Precedence rules for Operators
Boolean Expression

1. ( ) parentheses
2. , / ,
4. lt, gt, lt, gt
5. , !
8. If equal precedence, left to right

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Outline

• C Overview
• Boolean Expression
• Condition Statement

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Condition Statement

• if...else
• switchcase

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if statement syntax
if statement

• if (condition)
• statement

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Example if statement
if statement
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if statement syntax with multiple statements
if statement

• if (condition)
• statement1
• statement2

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ifelse statement syntax
if statement

• if (condition)
• statement1
• else
• statement2

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Example ifelse statement
if statement
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Nested IF
if statement
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Example Nested IF
if statement
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Summary

• C Overview
• Boolean Expression
• Condition Statement