The way if statements can be nested, similarly whiles and for's can also be nested. To understand how nested loops work, look at the program given below:
\* C Program to show the use of Nesting of Loop *\
# include < stdio.h >
int main( )
{
int r, c, sum ;
for ( r = 1 ; r <= 3 ; r++ )
{
for ( c = 1 ; c <= 2 ; c++ )
{
sum = r + c ;
printf("\n r = %d c = %d sum = %d ", r, c, sum) ;
}
}
return ( 0 );
}
r = 1 c = 1 sum = 2
r = 1 c = 2 sum = 3
r = 2 c = 1 sum = 3
r = 2 c = 2 sum = 4
r = 3 c = 1 sum = 4
r = 3 c = 2 sum = 5