Learn / JavaScript Fundamentals

Values & arrays

The data structures you'll touch in every JavaScript program.

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Lessons in this class

JavaScript: array methods

javascript · 4 steps · free

map, filter, and reduce without a loop in sight.

  1. console.log
  2. map
  3. filter
  4. reduce

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Also coming to this class

Variables & typesObjects

How CodeTrain teaches this

No videos and no multiple-choice quiz at the end. Each lesson is a handful of small steps in a real editor. You type the code yourself, it runs, and the tutor reviews what you actually wrote. It will not hand you the answer, and the step doesn't advance until your code passes. What you get at the end is a record of which steps you wrote unaided, not a completion percentage.

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