For Each Lab


  1. Practice using forEach
  2. Practice passing functions as callbacks


You'll be editing index.js and running tests as usual.

  • Define a function, iterativeLog(), that accepts an array. Call .forEach() on this array, and inside the callback, log each element with the format ${index}: ${element}.
  • Define a function, iterate, that accepts a callback. Within the iterate() function, you should initialize an array. It can contain anything you want, but make sure that it is not empty! Call .forEach() on this array, passing the callback to .forEach(). Then return the array that you initialized.
  • Define a function, doToArray that accepts an array and a callback. Call .forEach() on the array, passing the callback as the forEach callback.

Remember, you can run the tests using in the browser if you'd like — then read the results, refresh the page, and keep going afterwards.

Note: If you're using the Learn IDE, this is how to use

  1. Type "httpserver" into your learn IDE console.
  2. Type the ip it gives you into your browser. (The ip will look something like this:
  3. Go to your browser's console and type and press .
  4. Any errors from your code will now appear in your browser on the tab in which you typed your ip in step 2.
  5. Debug, editing your work in index.js, saving it, and repeating steps 3-5 until all tests pass.


View forEach() Lab on and start learning to code for free.

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