C program to convert a decimal number into binary number using function. In this example, we convert the decimal number entered by the user into binary form. Here, in the out put we have taken a decimal number 20 whose binary is printed as 10100. You can take other numbers such as 15, 13 78, etc... PROGRAM TO CONVERT A DECIMAL NUMBER INTO BINARY NUMBER USING FUNCTION. #include <stdio.h> #include <conio.h> int binary( int b ); void main() { int b; printf( "\nEnter the Number You want to convert : " ); scanf( "%d" , &b); binary(b); getch(); } int binary( int b ) { int a[10], i, j; for (i = 0; b > 0; i++) ...