Finding products by for loop:

an illustration, when 5 is passed to be the value of the input argument n, the function will compute and return 1 + 2 + 3 + 4 + 5, or 15:

>> sum_1_to_n(5)

  ans =

    15

Note that the output was suppressed whenever initializing the sum to 0 and when adding to it throughout the loop.

The other very general application of a for loop is to find a running product. For illustration, rather than of finding the sum of the integers 1 through n, we can find the product of the integers 1 through n. Principally, we want to implement

or compute the product 1 * 2 * 3 * 4 *... * n, that is known as the factorial of n, written n!.