Dictionaries

main (print)

main()
    ages = [str -> int: "Ada" -> 36]
    # Insert or replace, consuming the old dictionary.
    ages = [*ages, "Lin" -> 41]
    ages = [*ages, "Ada" -> 37]
    # lookup returns a result, since the key may be missing.
    ada = lookup(ages, "Ada") ?: 0
    nobody = lookup(ages, "Bo") ?: 0 - 1
    n = len(ages)
    print.line("{ada} {nobody} {n}")

37 -1 2