When loops are nested does one loop have to end before the other begins?

Answer 1

If one loop ends before the next begins then they are not nested at all -- they are completely independent. To be nested, one loop must contain the other loop in its entirety. That is, the inner, nested loop must start and end within the outer, containing loop.

Nested loop example (in C++):

for( int x = 0; x < 10; ++x ) // outer loop

{

for( int y = 0; y < 10; ++y ) // inner loop (nested loop)

{

printf( "%d x %d = %d\r\n", x, y, x*y );

} // end of inner loop

} // end of outer loop

Answer 2

In any programming language, the prime function of a loop is to carry on a desired function till the desired result is achieved. nested loop is a loop within a loop, an inner loop within the body of an outer one. The first clearance of the outer loop initiates the inner loop, which executes till the aim is achieved. Then the second clearance of the outer loop triggers the inner loop again. This repetition goes on until the outer loop finishes. A break within either the inner or outer loop would interrupt this process.

- JP Morgan