From the course: Mastering Web Developer Interview Code
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How would you use JavaScript reduce()?
From the course: Mastering Web Developer Interview Code
How would you use JavaScript reduce()?
- [Narrator] Reduce is a higher order function just like the map method we covered in the previous week. Now it's the sign to solve a common problem going over a list of elements and retrieving a single value related to them as the result. So let's take a look at how we would do that with traditional JavaScript. So you probably create something like a variable to hold a running total and then you will create some sort of array to hold the list of elements you want to go through. And then you would use perhaps something like a for loop to iterate through those different array items so you would maybe take that total value and continue to add the values of each of the elements in the array. This is a little bit messy and map is designed to solve this problem. That is a very common pattern in JavaScript. So let's take a look at how that looks with reduce. Now, reducing we'll take a callback where you can pass along a…
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Contents
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How do you use the data- attribute in HTML?11m 14s
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Are you comfortable using jQuery?11m 32s
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Describe when you should use the bind() method5m 21s
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Do you know how to use the conditional operator?3m 43s
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Have you used Ajax to load an external file?8m 25s
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Have you used JavaScript templates?7m 3s
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How does an IIFE work?7m 12s
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How does immutability work in JavaScript?4m 12s
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How would you use JavaScript reduce()?3m 54s
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What is a callback and how do you use it?8m 51s
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