KONTROL ALUR EKSEKUSI PROGRAM

Presentasi berjudul: "KONTROL ALUR EKSEKUSI PROGRAM"— Transcript presentasi:

1 KONTROL ALUR EKSEKUSI PROGRAM
BY : ZARNELLY,S.KOM,MSc

2 Kontrol Alur Eksekusi Kontrol Alur Eksekusi dibagi atas tiga bagian besar : Seleksi Looping Jump

3 Seleksi Perintah Seleksi dalam java : If If..else If jamak switch

4 Syntax Pemakaian IF If (kondisi) statement; [grade >= 60]
print “Passed”

5 Syntax Pemakaian if..else
If (kondisi) statement-1; else statement-2; [grade >= 60] [grade < 60] print “Failed” print “Passed”

6 Syntax Pemakaian if..else jamak
If (kondisi-1) statement-1; else if (kondisi-2) statement-2; else if (kondisi-3) statement-3; else default_statement

7 Syntax Pemakaian switch
switch (ekpresi) { case nilai1: statement1; break; case nilai2: statement2; case nilai_n: statement_n; default : statementdefault; }

8 Contoh Program dengan IF jamak
// Fig. 2.20: Comparison.java // Compare integers using if statements, relational operators // and equality operators. 4 // Java packages import javax.swing.JOptionPane; 7 public class Comparison { 9 // main method begins execution of Java application public static void main( String args[] ) { String firstNumber; // first string entered by user String secondNumber; // second string entered by user String result; // a string containing the output 16 int number1; // first number to compare int number2; // second number to compare 19 // read first number from user as a string firstNumber = JOptionPane.showInputDialog( "Enter first integer:" ); 22 // read second number from user as a string secondNumber = JOptionPane.showInputDialog( "Enter second integer:" ); 26 // convert numbers from type String to type int number1 = Integer.parseInt( firstNumber ); number2 = Integer.parseInt( secondNumber ); // initialize result to empty String result = "";

9 if ( number1 == number2 ) result = result + number1 + " == " + number2; 36 if ( number1 != number2 ) result = result + number1 + " != " + number2; 39 if ( number1 < number2 ) result = result + "\n" + number1 + " < " + number2; 42 if ( number1 > number2 ) result = result + "\n" + number1 + " > " + number2; 45 if ( number1 <= number2 ) result = result + "\n" + number1 + " <= " + number2; 48 if ( number1 >= number2 ) result = result + "\n" + number1 + " >= " + number2; 51 // Display results JOptionPane.showMessageDialog( null, result, "Comparison Results", JOptionPane.INFORMATION_MESSAGE ); 55 System.exit( 0 ); // terminate application 57 } // end method main 59 60 } // end class Comparison

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11 Contoh program dengan switch
class TestSwitch2 { public static void main(String[] args) { int bulan = 4; switch(bulan) { case 1: System.out.println("pertama"); case 2: System.out.println("kedua"); case 3: System.out.println("kuartal 1"); break; case 4: case 5:

12 Output kuartal 2 keluar dari switch case 6:
System.out.println("kuartal 2"); break; case 7: case 8: case 9: System.out.println("kuartal 3"); default: System.out.println("kuartal 4"); } System.out.println("keluar dari switch"); Output kuartal 2 keluar dari switch

13 Looping Terdapat 3 jenis perintah looping : While Do..while for

14 While Adalah jenis perulangan Benar, artinya perulangan akan dilakukan jika kondisi bernilai benar Syntax untuk statement tunggal while (kondisi) statement; Syntax untuk statement banyak { blok statement; }

15 While merge decision [product <= 1000] double product value
Corresponding Java statement: product = 2 * product;

16 Contoh program dengan while
1 // Fig. 4.7: Average1.java 2 // Class-average program with counter-controlled repetition. 3 import javax.swing.JOptionPane; 4 5 public class Average1 { 6 public static void main( String args[] ) { int total; // sum of grades input by user int gradeCounter; // number of grade to be entered next int grade; // grade value int average; // average of grades 13

17 14 String gradeString; // grade typed by user
15 // initialization phase total = 0; // initialize total gradeCounter = 1; // initialize loop counter 19 // processing phase while ( gradeCounter <= 10 ) { // loop 10 times 22 // prompt for input and read grade from user 24 gradeString = JOptionPane.showInputDialog( "Enter integer grade: " ); 26 // convert gradeString to int grade = Integer.parseInt( gradeString ); 29

18 30 total = total + grade; // add grade to total
31 gradeCounter = gradeCounter + 1; // increment counter 32 } // end while 34 // termination phase average = total / 10; // integer division 37 // display average of exam grades JOptionPane.showMessageDialog( null, "Class average is " + average, "Class Average", JOptionPane.INFORMATION_MESSAGE ); 41 System.exit( 0 ); // terminate the program 43 } // end main 45 46 } // end class Average1

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20 Average1.java

21 Perulangan Do..While Pada perulangan ini penyeleksian kondisi dilakukan dibagian akhir sehingga blok statement akan diakses minimal satu kali baik dalam kondisi benar atau salah. Syntax do { blok statement; } while (kondisi);

22 Contoh do..while class TestIter2 {
public static void main(String[] args) { int b = 9 ; System.out.println("Sebelum do"); do { System.out.println("Nilai b : "+b); b--; } while (b>=10); System.out.println("Setelah do"); } Output Sebelum do Nilai b : 9 Setelah do

23 Perulangan For Syntax For (inisialisasi;kondisi;iterasi) statement; Inisialisasi untuk menginisialisasi variabel yang menjadi pengontrol perulangan Kondisi pernyataan yang akan dieksekusi yang mengembalikan nilai benar atau salah Iterasi adalah pernyataan yang menjadi pengontrol jumlah perulangan Contoh : for(n=0;n<5;n++)

24 Contoh for class TestIter3 { public static void main(String[] args) {
int c; System.out.println("Sebelum for"); for(c=0;c<5;c++) System.out.println("Nilai c: " + c); System.out.println("Setelah for"); } Output Sebelum for Nilai c: 0 Nilai c: 1 Nilai c: 2 Nilai c: 3 Nilai c: 4 Setelah for

25 Latihan Soal Buat program dlm java menggunakan if atau case untuk menentukan apakah sebuah bilangan adalah ganjil atau genap Buat program dlm java untuk mencetak deret , gunakan looping

26 Jawab 1 // Fig. 2.9: Addition.java
// Addition program that displays the sum of two numbers. // Java packages import javax.swing.JOptionPane; // program uses JOptionPane public class GenapGanjil { // main method begins execution of Java application public static void main( String args[] ) { String bil; // first string entered by user int Genap; // first number to add int Ganjil; // second number to add // read in first number from user as a String bil = JOptionPane.showInputDialog( "masukkan bilangan" );

27 // convert numbers from type String to type int
Genap = Integer.parseInt( bil ); // add numbers if (Genap%2== 0) // display result JOptionPane.showMessageDialog(null, + Genap +" bilangan Genap", "Results", JOptionPane.PLAIN_MESSAGE ); else JOptionPane.showMessageDialog(null, + Genap +" bilangan Ganjil", System.exit( 0 ); // terminate application with window } // end method main } // end class Addition

28 Jawaban 2 // Addition program that displays the sum of two numbers.
// Java packages import javax.swing.JOptionPane; // program uses JOptionPane public class Deret { // main method begins execution of Java application public static void main( String args[] ) { int bil=2; String Deret1=""; // add numbers while (bil<=10) Deret1 = Deret1 + bil + " "; bil=bil+2; } // display result JOptionPane.showMessageDialog(null,Deret1, "Results", JOptionPane.PLAIN_MESSAGE ); System.exit( 0 ); // terminate application with window } // end method main } // end class Addition Jawaban 2