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The "FastDOM Exercise" Lesson is part of the full, JavaScript Performance course featured in this preview video. Here's what you'd learn in this lesson:

In this exercise, students work with FastDOM.

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Transcript from the "FastDOM Exercise" Lesson

>> Steve Kinney: What I want you to try to do is go back, turns out that codepen from before has fast downloaded globally. What I'd love you to try is for the doubling of the bars, to try to use fast dot. Go ahead and we broke it out into two functions.

[00:00:15] We ran through the entire array of those boxes slash bars. We measured them all, then we ran through the array a second time and mutated them all. Could we use FASTON, which is basically starting out with almost the original code we had, wrap that in the measure, and then for when we mutate it, wrap that in faston.mutate and let's see what the differences are.