learn

Nine tracks

Each one asks you to commit before it explains anything. Getting it wrong first is the point: a page that showed the answer beside the question would be a page nobody predicts on.

1. 01

   Values and bindings

   What is in this binding right now?

   • What a name holds · 8 min
2. 02

   Hoisting, scope and the dead zone

   Does this name exist yet, and may it be read?

   • The scan that runs first · 10 min
3. 03

   The stack

   Which frame are we in, and what happens when it goes?

   • A call is a frame · 8 min
4. 04

   Objects, references and mutation

   Do these two names point at the same object?

   • How far a copy goes · 10 min
5. 05

   Closures

   Which binding did this function capture, and is it shared?

   • What a closure keeps · 10 min
6. 06

   this and prototypes

   What is this, and where did that method actually come from?

   • Where this comes from · 12 min
7. 07

   Control and failure

   Which line runs next?

   • What runs next · 10 min
8. 08

   The event loop

   In what order do these effects actually happen?

   • Why the log printed last · 12 min
9. 09

   Reading what was generated

   What does this return, and what did it change on the way?

   • Reading a helper a model wrote · 12 min