typescript typing practice

the thread through every rung

a bus timetable

20 rungs

1. 01 · say something

   calling a function

   first time you type" ( ) . ;

2. 02 · a name with a type on it

   an annotation

   first time you type, : =

3. 03 · a shape of its own

   an interface

   first time you type{ }

4. 04 · a part that might not be there

   an optional field

   first time you type?

5. 05 · one of a few

   a union of exact values

   first time you type|

6. 06 · a list of shapes

   an array with a type

   first time you type[ ]

7. 07 · a note to yourself

   a comment, and arithmetic

   first time you type* + - /

8. 08 · a choice

   if and else

   first time you type>

9. 09 · a name for a job, typed

   what goes in and what comes out

   first time you type<

10. 10 · go through them

    a loop over a typed list

    nothing new to reach for

11. 11 · words with values in them

    a template string

    first time you type$ `

12. 12 · is it the same?

    equality, and its opposite

    first time you type!

13. 13 · make a new list from an old one

    map

    first time you type'

14. 14 · keep only some of them

    filter, and two conditions

    first time you type&

15. 15 · when there is nothing there

    a fallback for a missing part

    nothing new to reach for

16. 16 · a quote inside a quote

    the other quote mark

    nothing new to reach for

17. 17 · every other hour

    the remainder, and a counting loop

    first time you type%

18. 18 · a shape that works for anything

    a type left blank until used

    nothing new to reach for

19. 19 · narrowing a union

    the type decides the answer

    nothing new to reach for

20. 20 · the whole thing

    everything so far, doing one job

    nothing new to reach for