control structures session 03 mata kuliah: m0874 – programming ii tahun: 2010
TRANSCRIPT
Control StructuresSession 03
Mata kuliah : M0874 – Programming IITahun : 2010
Bina Nusantara University
3
Outline Materi
•Pseudocode•Control Structure•If Selection Structure•If/else Selection Structure•While Repetition Structure•Assignment Operators•Increment and Decrement Operators•For Repetition Structure•Switch Multiple-Selection Structure•Do/While Repetition Structure•Statements break and continue
Bina Nusantara University
4
Pseudocode
•An artificial an informal language that helps programmers develop algorithms.•Similar to everyday english; it is convenient and user-friendly, and it is not an actual computer programming language.•Not executed on computers.•Helps the programmer “think out” a program before attempting to write it in a programming language.
Bina Nusantara University
5
Control Structure
•Three types of selection structures:•If selection structure•If/else selection structure•Switch selection structure
•Four repetition structures:•While•Do/while•For•Foreach
Bina Nusantara University
6
If Selection Structure
If student’s grade is greater than or equal to 60Print “passed”
Pseudocode if statement:if ( studentGrade >= 60 )
Console.WriteLine ( “Passed” );
Bina Nusantara University
7
Flow chart If Selection Structure
Bina Nusantara University
8
If/else Selection Structure
If student’s grade is greater than or equal to 60Print “Passed”
elsePrint “Failed”
Pseudocode if/else structure:if ( studentGrade >= 60 )
Console.WriteLine( “Passed” );else
Console.WriteLine( “Failed” );
Bina Nusantara University
9
Flow Chart If/else Selection Structure
Bina Nusantara University
10
Nested if/else
if student’s grade is greater than or equal to 90Print “A”
elseif student’s grade is greater than or equal to 80
Print “B”else
if student’s grade is greater than or equal to 60
Print “C”else
Print “D”
Bina Nusantara University
11
Nested if/else
Pseudocode may be written as:if ( studentGrade >= 90 )
Console.WriteLine ( “A” );else
if ( studentGrade >= 80 )Console.WriteLine ( “B” );
elseif ( studentGrade >= 60 )
Console.WriteLine( “C” );else
Console.WriteLine( “D” );
Bina Nusantara University
12
Nested if/else
Most C# programmers prefer to write the preceding if structure as:if ( studentGrade >= 90 )
Console.WriteLine ( “A” );else if ( studentGrade >= 80 )
Console.WriteLine ( “B” );else if ( studentGrade >= 60 )
Console.WriteLine( “C” );else
Console.WriteLine( “D” );
Bina Nusantara University
13
While Repetition Structure
•Specify that an action is to be repeated while a condition remains true.•The pseudocode statement
While there are more items on my shopping list
Purchase next item and cross it off my listExample:
int product = 2;while ( product <= 1000 )
product = 2 * product
Bina Nusantara University
14
While Repetition Structure
product <= 1000 product = 2 * producttrue
false
Bina Nusantara University
15
Assignment Operators
Assume: int c = 3, d = 5, e = 4, f = 6, g = 12
Assignment operator
Sample expression
Explanation Assigns
+= c += 7 c = c + 7 10 to c
-= d -= 4 d = d - 4 1 to d
*= e *= 5 e = e * 5 20 to e
/= f /= 3 f = f / 5 2 to f
%= g %= 9 g = g % 9 3 to g
Bina Nusantara University
16
Increment and Decrement Operators
Bina Nusantara University
17
Increment and Decrement Operators
Bina Nusantara University
18
Increment and Decrement Operators
•Output:
For Repetition Structure
for keyword counter variable name final value of control variable
for ( int counter = 1; counter <= 5; counter++ )
Initial value of control variable loop-continuation condition increment of control varBina Nusantara
University19
for ( expression1; expression2; expression3 )statement
Bina Nusantara University
20
For Repetition Structure
Bina Nusantara University
21
For Repetition Structure
Bina Nusantara University
22
Switch Multiple-Selection Structure
Bina Nusantara University
23
Do/While Repetition Structure
•Do/while repetition structure is similar to the while structure.•In the while structure, the test of the loop-continuation condition occurs at the beginning of the loop, before the body of the loop executes.•The do/while structure tests the loop-continuation condition after the loop body executes; therefore, the loop body always executes at least once.
Bina Nusantara University
24
Do/While Repetition Structuredo do
statement OR {while ( condition ); statement
} while ( condition );
25
Do/While Repetition Structure
Bina Nusantara University
26
Statements break and continue
•The break and continue statements alter the flow of control.•The break statement, when executed in a while, for, do/while or switch structure, cause immediate exit from that structure.•The continue statement, when executed in a while, for or do/while structure, skips the remaining statements in the body of that structure and proceeds with the next iteration of the loop.
Bina Nusantara University
27
Statements break and continue
Bina Nusantara University
28
Statements break and continue
Bina Nusantara University
29
References
•http://books.google.co.id/books?id=8R451rZJ5o0C&printsec=frontcover&dq=c%23&cd=2#v=onepage&q=&f=false