Data Structures
How you store and manipulate data.
MapsCompletion percentage: 92.4% (21954)Completion percentage: 92.4% (21954)
Completion percentage: 92.4% (21954)
Completion percentage: 92.4% (21954)
The Map object holds key-value pairs and remembers the original insertion
order of the keys. Any value (both objects and
primitive values) may be used as
either a key or a value.
2019
2020
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| Never heard of it |
SetsCompletion percentage: 92.6% (22010)Completion percentage: 92.6% (22010)
Completion percentage: 92.6% (22010)
Completion percentage: 92.6% (22010)
The Set object lets you store unique values of any type, whether primitive values or object references.
2019
2020
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We asked members of the JavaScript community to share their “pick of the year”
My 2020 Pick: Josh W. Comeau
Josh Comeau has been an inspiration to me, and I can say the JS community in general. He writes very thoughtful articles on his blog, and they are some of the best I read in 2020 because they either helped me stay on top of the latest in JavaScript or helped me learn something new.
We asked members of the JavaScript community to share their “pick of the year”
Gift Egwuenu
Frontend Developer @ PassionatePeople
Typed ArraysCompletion percentage: 92.7% (22032)Completion percentage: 92.7% (22032)
Completion percentage: 92.7% (22032)
Completion percentage: 92.7% (22032)
JavaScript typed arrays are array-like objects that provide a mechanism for reading and writing raw binary data in memory buffers.
2019
2020
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| Never heard of it |
Array.prototype.flat()Completion percentage: 93% (22108)Completion percentage: 93% (22108)
Completion percentage: 93% (22108)
Completion percentage: 93% (22108)
The flat() method creates a new array with all sub-array
elements concatenated into it recursively up to the specified depth.
2019
2020
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| Never heard of it |
BigIntCompletion percentage: 93.4% (22186)Completion percentage: 93.4% (22186)
Completion percentage: 93.4% (22186)
Completion percentage: 93.4% (22186)
BigInt is a built-in object whose constructor returns a bigint primitive — also called a BigInt value, or sometimes just a BigInt — to represent whole numbers larger than 2^53 - 1 (Number.MAX_SAFE_INTEGER), which is the largest number JavaScript can represent with a number primitive (or Number value). BigInt values can be used for arbitrarily large integers.
2020
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Recommended Resources
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