Pert 4: Control Structure

Tujuan

• Memahami struktur kontrol program• Dapat menerapkan:– If– While– Do while– For Dalam pembuatan program sederhana

Materi Hari ini

Alur program

Terurut

Percabangan

Perulangan

A control statement in a programming language is a

statement that allows the compiler to alter its normal execution of line-by-line execution of code.

Mengenal Boolean

True

False

16>10

16<10

boolean benar=true;boolean lulus=false;

Decision

Outcome 1 Outcome 2

Optio

n 1 Option 2

Model Keputusan I

Heads or TailsAnother example of a decision is the one involved in ‘‘heads you win, tails you lose.’’ If you flip a coin and the head appears, then you have won. The otheroption is that the tail appears and you have lost.

How to Spend Allowance If you spend it on a shirt you like, you will not have money for a CD. So you must make a decision.

Terdapat dua option (pilihan), jika nilai>=60 maka akan dicetak “Lulus”, dan jika nilai kurang dari 65

maka dicetak “Tidak Lulus”

nilai>=65

Int nilai=60

Print “Lulus”

Yes

Print “Tidak Lulus”No

Ternyata nilai=60 maka pilihan yang ada akan jatuh pada Option 2, maka akan

dicetak “Tidak Lulus”

Model Keputusan II

Decision

Outcome 1

Opti

on 1

Option 2 has no outcome

nilai>=65

Int nilai=60

Print “Lulus”

Yes

Terdapat dua option (pilihan), jika nilai>=60 maka akan dicetak “Lulus”,

dan jika nilai kurang dari 65 maka dicetak “Tidak Lulus”

Ternyata nilai=60 maka pilihan yang ada akan jatuh pada Option 2, tapi option 2

tidak ada outcome

Statemen if

When you buy an item from an online vendor, a $5.00 shipping fee is waived for purchases of $25.00 or more.Problem Statement Write a program that calculates the fi nal cost of an item, including sales tax and shipping, if applicable. Sales tax is 8% of the purchase price.

Output

sale < 25.0

total SHIPPING_FEE;System.out.println("Shipping is $5.00");

if (kondisi pilihan){//statemen ketika kondisi true

}int jumlah=100;if(jumlah>50){ System.out.println(“Lebih dari 50”);}

Nilai booleanTrue False

Examples• If amount of the check is less than the balance,

boolean expression• subtract the amount of the check from the balance.

conclusion• If password entered at the keyboard is the same as the true

password,boolean expression

• provide access to the account.conclusion

• If your age is greater than 16,boolean expression

• apply for your driver’s license.conclusion

A loop around a horse’s neck, a circus ring, and a loop around the thoughts in a cartoon character’shead are all shown.

A loop brings to mind a circular

image.

a part of a program thatyou execute over and over again until you are permitted to leave

that part to get to another programming statement

A person drives a car back home (‘‘loops back’’) to pick up a friend who is standing next to the house

In a program, a loop describes a group of one or more lines of

code that must berepeated some number of times

Computers, unlike humans, are tireless, experiencing neither boredom nor fatigue.

Repeating an operation millions of times presents no problem to a computer with an internal clock

that ticks billions of times every second

Loop

While

Do While

For

Whi

leEkpresii Boolean

(kondisi)

Statement 1

Statement 2

Statement n

Statement after loop

True

False

Example while loop

• Problem Statement Write a program that sums a list of integers supplied by a user. The list can be of any size. The program should prompt the user for the number of data.

• Java Solution The following application utilizes three variables: size, sum, and count .– size is the number of data;– sum holds a running sum of the numbers supplied by the user

so that each time the– user enters a number, that number is added to sum ; and– count keeps track of the number of data.

Variables sum and count are initialized to 0; the value of size is supplied by the user. The addition is accomplished using a while loop similar to the loop in the segment that precedes this example.

0 0

sum count size

0 0 3

sum count size

5 1 3

sum count size

12 2 3

sum count size

21 3 3

sum count size