/*
This happens because declaring variables inside a for loop 
wasn't valid C until C99(which is the standard of C published in 1999), 
you can either declare your counter outside the for
or use the -std=c99 flag to tell the compiler explicitly 
that you're using this standard and it should interpret it as such.
*/
int j;
for(j=0;j<5;j++)
printf("%d",Arr[j]);