May 2018
Intermediate to advanced
376 pages
9h 22m
English
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Lesson 25. Maps
After reading lesson 25, you will
- Know to create a Map
- How to convert a plain object into a Map
- How to add and access values on a Map
- How to iterate the keys and values from a Map
- How Maps are destructured
- Understand when it makes sense to use a Map over an Object
- Understand why it makes sense to use a WeakMap over a Map
Like Sets, Maps are a new type of object in JavaScript. Not to be confused with Array.prototype.map, which is a higher-order array method, Maps are another type of iterable that’s new to JavaScript in ES2015. A Map is a lot like a generic object in JavaScript with keys and values. But a Map can be iterated, whereas an object can’t. Plain objects are also limited to only being able to have string values as ...
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