Fungsi (FUNCTION) pada C++

Pendahuluan (Preliminary)

(English Version) The function is a block of program code designed to perform specific tasks. The function of many involved in the creation of a program, with the aim of:
The program became more tersetuktur, making it easy to understand and easy to develop
Can reduce code duplication.
The general form of a function is as follows:

Tipedata namafungsi(daftarparameter) { /*Badan Fungsi*/ return nilaireturn; /* untuk tipe data bukan void */ }

(English Version) Functions of type void
Functions of type void, if the pascal or delphi program called procedure. This function has no return value, so the function of this type is just a bunch of code that works in accordance with the given parameters.
Examples of functions of type void:

void TampilNama() { textcolor(RED); cprintf(“Nama Saya : Tulis Nama Anda\n\r”); cprintf(“Alamat    : Jl. Can Di Aspal No. 70\n\r”); cprintf(“Telepon   : 022-2513709\n\r”); } main() { TampilNama(); TampilNama(); TampilNama(); }

(English Version) In the above program, there is a function called TampilNama (), which is useful for displaying data Name, Address, and Phone. In the main program (function main ()), how to call a function is to write the name of the function (in this case TampilNama ()). So the above program will display the contents TampilNama function () 3 times.
The above function is a function called without using parameters. To see examples of parameterized functions, consider the program below.

void Kotak(int X1,int Y1, int X2,int Y2,int Bingkai,int Latar) { int i; textcolor(Bingkai); textbackground(Latar); gotoxy(X1,Y1);cprintf(“é”); /* alt+218 */ gotoxy(X1,Y2);cprintf(“%c”,192); gotoxy(X2,Y1);cprintf(“%c”,191); gotoxy(X2,Y2);cprintf(“%c”,217); for (i=X1+1;i<=X2-1;i++) { gotoxy(i,Y1);cprintf(“%c”,196); gotoxy(i,Y2);cprintf(“%c”,196); } for(i=Y1+1;i<=Y2-1;i++) { gotoxy(X1,i);cprintf(“%c”,179); gotoxy(X2,i);cprintf(“%c”,179); } } main() { Kotak(1,1,80,24,WHITE,BLUE);// Memanggil Procedur Kotak Kotak(2,2,15,23,WHITE,RED); getch(); return 0; }

(English Version) Void Box is a function that will create a box on the screen according to the coordinates given in the parameter. These coordinates are the top left coordinates (X1, Y1), and the coordinates of the lower right (X2, Y2). Besides this function requires a parameter that is useful for determining frame box frame color, as well as a useful parameter for determining background color background made box.
Dialling Box (1,1,80,24, WHITE, BLUE) allows you to create a box with upper left position on the coordinate (1,1) and bottom right position at coordinates (80.24) with the color white box frame with background blue box.
Function data type
In the world of mathematics, we know the function. Example: F (X) = X ² +3 X +5, which means we have a function named F which takes the parameter X as the data to be calculated by the equation x ² +3 x +5 so if we write F (5), then the value of the function is 5 ² + 3.5 + 5 = 45.
The general form of this function in the Pascal language is:
typedata NamaFungsi (list parameters)
{
Commands;
Commands;
Return NilaiHasilUntukFungsi;
}
Example 1: Function to calculate mathematical equations F (X) = X ² +3 X +5;

float F(float X) { return X*X+3*X+5;//Fungsi diisi hasil dari perhitungan X2+3*X+5 }

(English Version) Example 2: Function to find the factorial of a value

float Faktorial(int N) { int I; float Hasil; Hasil:=1; for(I=2;I<=N;I++) Hasil=Hasil * I; return Hasil; }

(English Version) Example 3: The function to look for combination with the formula:
The combination of (X, Y) =

Float  Kombinasi(int X, int Y) { return Faktorial(Y) / (Faktorial(X)*Faktorial(Y-X)); }