Collections and repeated work

15-minute session: read for 3 minutes, trace for 3, experiment for 7, and complete the check for 2. Spend longer whenever you need.

A collection stores related values. The loop visits 1, 2, and 3, updating the total from 0 to 1, then 3, then 6. Record this trace rather than guessing. Identify the first and last valid positions in this language: Pascal can declare a 1-based array, while many other examples use zero-based containers. Add another value and update the bounds correctly. Explain what an empty collection should produce.

:= declares a value. Add mut only when it must change. !int describes a result that may fail; the caller handles the failure with an or block. Standard V examples do not import the Agila SDK.


fn main() {
    minutes := [1, 2, 3]
    mut total := 0
    for value in minutes { total += value }
    println(total)
}

Expected result: 6

Practice and evidence

Keep three notes: your prediction, the actual result, and why they match or differ. The completion check grades understanding; the practice task builds skill.

Language reference