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Lesson 0 of 11

3 min

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In this track you type instructions, as lines of text.

One line at a time, top to bottom.

This track is Programming Proper I.

The editor is the screen where you type your program. The editor here is stricter than most real tools. It refuses some lines that those tools allow. That is on purpose: it tells you what is wrong.

What you will do

  • Typing it out. One line, one instruction. Top to bottom.
  • `let` and `const`. A box you can refill, and one you cannot.
  • Four kinds of value. Number, text, true or false, nothing.
  • What the signs do. Arithmetic, and one sign with a second job.
  • A fork in the line. A block that runs only if true.
  • Until it stops. A loop that runs while a check is true.
  • Once for each. A loop with one turn per list item.
  • What the message says. What a machine tells you when it stops.

Need a quick recap?

  • Variables — a named box, holding one value at a time.
  • Repeat — a block that runs a set number of times.
  • If/then — a block that runs only when a check passes.