Here is a basic way to get the octal value of a decimal number. In this program, a for loop is used which will get the remainder, decrease the number by dividing it by 8 and populate the array. At the end, we will simply print the array in reverse order.
#include<iostream.h> #include<conio.h> void main() { int num,rem,div,i=0,a[100]; cout<<"Enter the number : "; cin>>num; //getting the number for (div=num/8;div>0;) { if (i==0) rem=num%8; else { rem=div%8; //dividing the number by 8 to get remainder and getting new number div=div/8; } a[i]=rem; //populating the array with remainder i++; } cout<<endl<<"The Octal Value of given number is : "; for (int k=i-1;k>=0;k--) cout<<a[k]; //printing the array in reverse order getch(); }