I dont understand.

#include <stdio.h>
int main()
{
    int ara[]={10,20,30,40,50,60,70,80,90,100};
    int temp;
    int i,j;

     for(i=0,j=9;i<10;i++,j--)
    {
       temp=ara[j];
       ara[i]=temp;
       printf("%d\n",ara[i]);
    }


    return 0;
}