52 — Sorting — putting a list in order

A list stays in the order you wrote it. That is rarely the order you want to show — scores read best from the top, names read best in alphabetical order. There are only two sentences for putting a list in order.

#Steps

1. Make a list and look at it. joined by comma shows a list on one line:

   set scores to list of 5, 3, 9, 1
   show scores joined by comma
   

   copyrun it →

   5, 3, 9, 1 — exactly as written.

2. sort stands it up smallest first:

   set scores to list of 5, 3, 9, 1
   sort scores
   show scores joined by comma
   

   copyrun it →

   You get 1, 3, 5, 9. The list itself changes. From here on scores stays in that order.

3. Once it is standing, the two ends are your answer. Smallest first means the first item is the smallest and the last is the biggest:

   set scores to list of 5, 3, 9, 1
   sort scores
   show the first of scores
   show the last of scores
   

   copyrun it →

   1 and 9.

4. reverse turns it around. Reversing a sorted list gives biggest first:

   set scores to list of 5, 3, 9, 1
   sort scores
   reverse scores
   show scores joined by comma
   

   copyrun it →

   9, 5, 3, 1. That is the order a score table is written in.

5. Words stand up too. Numbers go smallest first, words go alphabetically:

   set names to list of Zoe, Mina, Ada
   sort names
   show names joined by comma
   

   copyrun it →

   You get Ada, Mina, Zoe.

6. The whole thing:

   set scores to list of 5, 3, 9, 1
   show as written
   show scores joined by comma
   sort scores
   show smallest first
   show scores joined by comma
   show the first of scores
   show the last of scores
   reverse scores
   show biggest first
   show scores joined by comma
   

   copyrun it →

#Try it yourself

Put show the biggest of scores at the very top, before any sorting. It finds the biggest without standing the list up at all. Sorting is what you do when you want to see all of it in order.

#What you learned

• sort <list> stands a list up smallest first, or alphabetically for words.
• reverse <list> turns the current order around. After sorting, that is biggest first.
• Both change the list itself. The original order is gone.
• After sorting, the first is the smallest and the last is the biggest.