Loops can involve many repetitions, so printing during each pass through a loop is often impractical and undesirable. In some cases, a message or other clean$-$up work is done after the loop is finished.

Example $5$ Compute the average of a list of numbersThe expression x$=$ rand $(1,$n$)$ creates a row vector of n pseudo$-$random numbers. The expression s$=$s$+$x$($i$)$ adds the ith element of x to the sum. As in Example $4,$ an initial value of s must be assigned before the loop starts. The average value $($xbar$)$ can only be computed after the loop is finished.