Matakuliah
Tahun
Versi
: T0026/Struktur Data
: 2005
: 1/1
Pertemuan 2
Data Komposit Structure
1
Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
• Mahasiswa dapat menghasilkan program
modular yang menggunakan structure of
structure.
2
Outline Materi
•
•
•
•
•
•
Deklarasi Structure
Akses data elemen struct
array of struct
Structure of structure
struct sebagai parameter fungsi
contoh program dengan struct
3
Definisi Structure
• Elemen array : heterogen
• Elemen struct disebut field
• Akses elemen array : random melalui
nama_struct.nama_field
• Penempatan field dalam memory : berurutan,
secara logikal dan fisikal
• Jumlah dan tipe field menentukan jumlah
memori
4
Contoh Structure
Hubungan antara file-structure-field :
FIELD
FILE/TABLE
Matakuliah
KodeMTK
NamaMTK
SKS
T0026
Struktur Data
6
A0102
Pancasila
2
ME351
Kalkulus
4
STRUCTURE/RECORD
5
Pendeklarasian Structure
Syntax Pada C :
struct <struct_name>{
<type> <elemen_name1>;
<type> <elemen_name2>;
} <structure_variable>;
Contoh (1) :
struct Matakuliah{ char
KodeMTK[6];
char
NamaMTK[40]
int
SKS; };
Variabel X dg tipe struct Matakuliah didefinisikan :
struct Matakuliah X;
Contoh (2) :
struct Matakuliah{ char
KodeMTK[6];
char
NamaMTK[40]
int
SKS; } X, Y;
Contoh (3):
struct {
char
KodeMTK[6];
char
NamaMTK[40]
int
SKS; } X;
6
Deklarasi struct
struct person {
char name[10];
int age;
};
name
age
10
10
a
2
10
a+10
Address person.name = a
Address person.age = a + 10
Jumlah memory = sizeof (name) + sizeof (int) = 12
7
Addressing pada Struct
• Address suatu field =
base address + ofset (field)
• Ofset (field) : jarak antara base address ke
awal field
8
Operasi pada Struct
• Create
Nama struct
struct person {
char name[10];
int age;
};
person
Nama
variabel
p1, *p2;
• Retrive
• Store
x = p1.age;
y = p2->age;
p1.name = “Andi”;
p2->name = “Ani”;
9
Akses Struct
complex c1;
complex *pc;
pc = (complex*) malloc(sizeof(complex));
atau
pc = &c1;
printf (“…”, &c1.re, c1.re, &c1.im, c1.im);
printf (“…”, &pc->re, pc->re, &pc->im, pc->im);
10
Passing Parameter(1)
struct complex{
float re;
float im;
};
complex add (complex cc1, complex cc2)
{
complex z;
z.re = cc1.re + cc2.re;
z.im = cc1.im + cc2.im;
return (z);
}
11
Passing Parameter(2)
void init (complex *px, float r, float i){
px->re = r; px->im = i;
}
void main()
{
complex c1, c2, c, *pc;
init (&c1, 5., 7.);
c = add (c1, c2);
init (&c2, 10., 13.);
12
Array of struct (1)
struct person{
char
name[10];
int
age;
address addr;
};
person
p[80], *pp;
struct address{
char street[10];
int number
};
Array p adalah array 1 dimensi.
Sizeof(person) = 12
Address p[50].name dan p[50].age ?
13
Array of struct (2)
pp = &p;
(*pp).name
pp->name
pp++
//pointer to struct hrs dialokasikan
Cara mengakses field dgn pointer
//geser ke structure berikutnya
14
Struct of struct
struct person{
char
name[10];
int
age;
address addr;
};
person
p[80], *pp;
struct address{
char
street[10];
int
number
};
Cara akses field
struct of struct :
p[i].addr.number
pp->addr.number
15