Pemrograman Dasar

Control Flow Statements:Repetition/Looping

PTIIK - UB

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Statements Control flow statements regulate the order in which statements get

executed. Kinds of control flow statements:

Decision making: if-then statement if-then-else statement, switch-case statement

Repetition/looping: while statement for statement do-while statement

Branching statement: break statement continue statement return statement

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Three forms of repetition statements: while statements for statements do-while statements

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Repetition/Looping

Syntax:while (boolean_exp) statement;

or

while(boolean_exp){

statement1;

statement2;

..

}

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boolean_expboolean_exp

statementsstatements

true

false

while statements

Example:

while(product <= 1000)

product = 2*product;

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product <= 1000

product=2*product;

false

true

while statements

break Exit from decision-making (switch) or repetition (for, while dan do-while)

continue Skips the current iteration of a for, while and do-while.

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break dan continue

Example:

int x = 1; while(x<=10){ System.out.println(x); x++; if (x>5)

break; }

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Exit from the loopExit from the loop

break

Example:

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int x; for(x=1; x<=10; x++) { if (x == 5)

continue; System.out.println(x); }

continue

Exercise

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int X2, Nilai, Rata-rata; float K, RND, Total;

String Nama, KodeMK, NamaKota, Fakultas;

No Pernyataan (statements ) B/S Alasan (jika salah)1 X2 = 3;

2 Nama = ”Amanda”;

3 3K = 8.71;

4 Nilai%3 = 3.16;

5 Rata-rata = 14;

6 KodeMK = CS512;

7 NamaKota = ”Malang”;

8 Fakultas = MIPA;

9 RND = 5.12 * N;

10 %Total = 71.8;

Exercise

Input:Berapakah kue untuk si Rakus? …

AsumsiMisalkan jawaban pertanyaan di atas adalah 5

Maka output-nya:Si Rakus melihat 5 kue, memakan 1, menyisakan 4Si Rakus melihat 4 kue, memakan 1, menyisakan 3Si Rakus melihat 3 kue, memakan 1, menyisakan 2Si Rakus melihat 2 kue, memakan 1, menyisakan 1Si Rakus melihat 1 kue, memakan 1, menyisakan piringnya

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Submission

Deadline: 21 October 2012To: ismiarta@gmail.comSubject: [PROGDAS SI…] Si RakusContent: Nama: NIM: Kelas: Table Source code

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for statements

You use the basic for statement to loop over a range of values from beginning to end.

for (initialization-expression; loop-expression; update-expression)

statement;

//or

for (initialization-expression; loop-expression; update-expression) {

statement;

…

}

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for (exp1; exp2; exp3)

statement;

exp1: initialization-expressionexp2: loop-expression exp3: update-expression

The initialization-expression allows you to declare and/or initialize loop variables, and is executed only once.

Then the loop-expression of boolean or Boolean type is evaluated and if it is true the statement in the body of the loop is executed.

After executing the loop body, the update-expression is evaluated, usually to update the values of the loop variables, and then the loop-expression is reevaluated. This cycle repeats until the loop-expression is found to be false.

The presence of exp1, exp2, and exp3 are optional.13

for statements

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exp1

exp3

statements

exp2true

false

exp1

exp3

statements

exp2

for statements

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Example: for (x=1; x <= 10; x++) System.out.println(“x =” + x);

x = 1

x++

System.out.println(“x =” + x);

x<=100true

false

for statements

Examples:

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int x;for(x=1; x<=10; x++) System.out.println(x);

int x; for(x=10; x>=1; x--) System.out.println(x);

for statements

exp1 and exp3 may consist of more than one expressions, separated by comma(s)

Examples:

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int i,j; for(i=1, j=30; i<j; i++, j--){ System.out.println(i + " -- " + j); }

for statements

Infinite Loopfor(;;){

…

}

Contoh:

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int i = 0; for(;;){

i++; printf("%d ", i);

if (i>=10) break; // break out of the loop

}

for statements

Equivalence of for and while:

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exp1;while(exp2){ statement1; statement2; …. exp3}

exp1;while(exp2){ statement1; statement2; …. exp3}

for(exp1; exp2; exp3){ statement1; statement2; ….}

for(exp1; exp2; exp3){ statement1; statement2; ….}

equivalentequivalent

while and for

Equivalence of for and while:

Contoh:

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int x; for(x=1;x<=10;x++) System.out.println(x);

exp1;while(exp2){ statement1; statement2; …. exp3}

exp1;while(exp2){ statement1; statement2; …. exp3}

for(exp1; exp2; exp3){ statement1; statement2; ….}

for(exp1; exp2; exp3){ statement1; statement2; ….}

equivalentequivalent

equivalent

while and for

int x=1; while(x<=10){ System.out.println(x); x++; }

Exercise

Input:Berapakah kue untuk si Rakus? …

AsumsiMisalkan jawaban pertanyaan di atas adalah 5

Maka output-nya:Si Rakus melihat 5 kue, memakan 1, menyisakan 4Si Rakus melihat 4 kue, memakan 1, menyisakan 3Si Rakus melihat 3 kue, memakan 1, menyisakan 2Si Rakus melihat 2 kue, memakan 1, menyisakan 1Si Rakus melihat 1 kue, memakan 1, menyisakan piringnya

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