Counting, Any, and All over an Array

These three patterns all walk through an array once, but they stop for different reasons. A counting loop never quits early: it checks every element against a condition and increments a counter each time the condition is true, because you need to see the whole array to know the total. An 'any' loop is impatient: it returns true the instant it finds one element that matches, because one success is enough to answer 'does at least one qualify?' You only reach the end and return false if nothing ever matched. An 'all' loop is also impatient, but in the opposite direction: it returns false the instant it finds one element that breaks the rule, because a single failure ruins the claim that every element qualifies. You only return true if the loop finishes with no failures found.

The reason you don't always need to look at every element comes down to what question you're asking. 'Any' and 'all' are existence questions — one piece of evidence, for or against, settles them. Counting is a tally question — missing even one element could change the answer, so there's no shortcut.

This topic sets up everything else in the unit. Searching an array for a target value is really an 'any' check with a twist: instead of just true or false, you report where the match was. Comparing consecutive pairs — used in checking if an array is sorted — reuses the same early-exit logic as 'all', just applied to arr[i] and arr[i+1] instead of a single element.