- Nesting of Definite Loops:
If both loops are definite loops, the following guidelines apply:
- The outer loop must be controlled using a definite loop-continuation condition, and the inner loop must also be controlled using a definite loop-continuation condition.
- The inner loop will iterate its complete set of iterations for each iteration of the outer loop, and the outer loop will iterate its entire set of iterations as the inner loop completes each of its iteration sets.
- Nesting of Indefinite Loops:
If both loops are indefinite loops, the following guidelines apply:
- Each loop must be controlled using an indefinite loop-continuation condition.
- Either loop can potentially execute indefinitely.
- If one of the loops executes indefinitely and the other does not, the looping process will never end.
- Nesting of a Definite and an Indefinite Loop:
If one of the loops is a definite loop and the other is an indefinite loop, the guidelines that apply to indefinite loops are used.
Here is an example of nested `for` loops in JavaScript to find the prime factors of a given number:
```javascript
function findPrimeFactors(number) {
// Initialize an empty array to store prime factors
let primeFactors = [];
// Iterate through all numbers from 2 to the square root of the input number
for (let i = 2; i <= Math.sqrt(number); i++) {
// If the input number is divisible by the current number without remainder
while (number % i == 0) {
// Add the current number to the list of prime factors
primeFactors.push(i);
// Divide the input number by the current number
number /= i;
}
}
// If the input number is greater than 1, it's a prime number, so add it to the list
if (number > 1) primeFactors.push(number);
// Return the list of prime factors
return primeFactors;
}
```
In the example above, the outer `for` loop iterates through all numbers from 2 to the square root of the input number. For each value of `i`, the inner `while` loop checks if the input number is divisible by `i`. If it is, the inner loop keeps dividing the number by `i` until it's no longer divisible, adding each `i` to the `primeFactors` array. Once the inner loop completes, the outer loop moves to the next value of `i`. The process continues until the input number is no longer divisible by any numbers other than itself. At that point, the input number is prime and is added to the `primeFactors` array. Finally, the function returns the `primeFactors` array.
Nesting loops can be used to solve various problems that require iterating over multiple sequences or data structures. They allow you to create complex control structures and perform different operations based on combinations of conditions.