42 — Word count: how often each word appears

"How often each word appears" is one number under each name, which makes it a record. There is only one hard part: a word seen for the first time and a word seen again have to be handled differently.

#Steps

1. Split the text into words:

   set text to apple pear apple plum
   set words to text split by space
   show how many words
   

   copyrun it →

   You get 4. A word that appears twice is in the list twice.

2. A word seen for the first time starts at one:

   set counts to an empty record
   put apple at 1 in counts
   show apple in counts
   

   copyrun it →

3. A word seen again is taken out, raised, and put back. Three steps:

   set counts to an empty record
   put apple at 1 in counts
   set seen to apple in counts
   add 1 to seen
   put apple at seen in counts
   show apple in counts
   

   copyrun it →

   You get 2.

4. What tells the two apart is whether it is already there:

   set counts to an empty record
   set word to apple
   if counts contains word
       show this is not the first time
   else
       show this is the first time
   end
   

   copyrun it →

   this is the first time.

5. The whole thing — one word at a time, one of the two things each time:

   set text to apple pear apple plum pear apple
   set words to text split by space
   set counts to an empty record
   for each word in words
       if counts contains word
           set seen to word in counts
           add 1 to seen
           put word at seen in counts
       else
           put word at 1 in counts
       end
   end
   for each word in counts
       show word
       show word in counts
   end
   show how many counts
   

   copyrun it →

   apple 3, pear 2, plum 1, and the final 3 is how many different words there were.

#Try it yourself

The same word in capitals is counted separately. Putting word in small letters into a name and counting that instead brings them together. Then show only the words seen more than once by testing the count in the last loop.

#What you learned

• One number under each name is a record.
• contains tells a first sighting from a repeat.
• Raising a number inside a record is take-out, add, put-back.
• how many on a record is the number of different names, not of items counted.