11st Semester 2005
Module4-1 Module4-1 Iteration statement - whileIteration statement - while
อภิ�รั�กษ์� จั�นทรั�สรั�างAphirak Jansang
[email protected]://www.cpe.ku.ac.th/~aphirak
Computer Engineering DepartmentKasetsart University, Bangkok THAILAND
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Outline Review condition statement Loop statements
while statement do…while statement for statement
break statement
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Simple C# Structure Namespace
Class Main()
NamespaceNamespace
ClassClass
Main()Main()
Variable & Constant LocationVariable & Constant Location
statementsstatementsWriteLine, ReadLine, if, switch, LoopWriteLine, ReadLine, if, switch, Loop
Review condition statementReview condition statement
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Condition Statements
if (conditioncondition) statement; if (conditioncondition)
statement1;else statement2;
switch (<(<expressionexpression>)>){ case <constant-expression>: <statements>; break;
default: <statements>; break;}
Review condition statementReview condition statement
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Outline Review condition statement Loop statements
while statement do…while statement for statement
break statement
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Loop or Iteration in C#
forfor
whilewhile
do…whiledo…while
foreachforeachIterationIteration
Loop statementsLoop statements
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C# Program with ConditionStart
statement1
statement2
statement3 statement4
End
Conditiontruetrue falsefalse
Loop statementsLoop statements
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Simple C# ProgramStart
statement1
statement1
statement1
statement1
End
statement1
Loop statementsLoop statements
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Simple C# Program with LoopStart
x=5;
statement1
x=x-1;
End
x>0
truetrue
falsefalse
Loop statementsLoop statements
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Outline Review condition statement Loop statements
while statement do…while statement for statement
break statement
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while statement
conditioncondition
statementstatement
truetrue
falsefalsewhile (condition) statement;
while statementwhile statement
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while statement – more statements
while (condition) { statement1; statement2;}
conditioncondition
statement1statement1
truetrue
falsefalse
statement2statement2
while statementwhile statement
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Example1:while statement
22nn = ??? = ??? n = 5n = 5
result=2*2*2*2*2result=2*2*2*2*2 = 32= 32
result=1;
result = result*2;
n=n-1;
n>0
truetrue
falsefalse
n=5;
Display resultDisplay result
See demo program!!!!See demo program!!!!prog2-loop.csprog2-loop.cs
while statementwhile statement
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Example2:while statement
n = 5n = 5
result = 1+2+3+4+5result = 1+2+3+4+5 result=0;
result = result+n;
n=n-1;
n>0
truetrue
falsefalse
n=5;
Display resultDisplay result
See demo program!!!!See demo program!!!!prog3-loop.csprog3-loop.cs
n
i
i1
while statementwhile statement
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Iteration Template Counter Controlled Sentinel Controlled
while statementwhile statement
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Counter Controlled Control Variable – counter variable
Three component Initial counter variable condition (counter variable is still valid?) Incrementing/Decrementing counter
variable
while statement: counter controlledwhile statement: counter controlled
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Example3:Count Controlled
Display 1 – 7 on screeninitial counter
statement;
dec||inc counter
condition
truetrue
falsefalse
See demo program!!!!See demo program!!!!prog4-loop.csprog4-loop.cs
while statement: counter controlledwhile statement: counter controlled
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Break!!!! (5 minutes)(Elevator) Neo: There is no spoon... Morpheus: Neo, sooner or later you're
going to realize, just as I did, there's a there's a difference between knowing the difference between knowing the path and walking the pathpath and walking the path......
Trinity: Run, Neo . Run ! What is he doing? Morpheus: He's beginning to believe* From The Matrix
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Iteration Template Counter Controlled Sentinel Controlled
while statementwhile statement
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Sentinel Controlled Input driven program
#repetition cannot tell depend on condition and input
Sentinel Value Causes loop to break
while statement: sentinel controlledwhile statement: sentinel controlled
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Example4:Sentinel Controlled
Find summation from user input Exit program when user input
negative number
See demo program!!!!See demo program!!!!prog5-loop.csprog5-loop.cs
while statement: sentinel controlledwhile statement: sentinel controlled
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Break 3 Minutes
““With With great powergreat power comes with comes with great responsibilitygreat responsibility””
*From Spiderman*From Spiderman
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Example 5: Display n stars
See demo program!!!!See demo program!!!!prog6-loop.csprog6-loop.cs
while statement: examplewhile statement: example
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Example 6: Display stars
See demo!!!!See demo!!!!prog7-loop.csprog7-loop.cs
while statement: examplewhile statement: example
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Example 7: Display stars
See demo!!!!See demo!!!!prog8-loop.csprog8-loop.cs
while statement: examplewhile statement: example
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Example 8: Display stars
See demo!!!!See demo!!!!prog9-loop.csprog9-loop.cs
while statement: examplewhile statement: example
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Summary Loop statements
while statement do…while statement for statement
break statement