JS TutorialLesson 22Free preview

JS Sets

This lesson is part of JavaScript · All levels

Summary

Sets are a collection of unique values, so storing double data is automatically discarded during manufacture or addition. The set provides methods add, delete, has, and clear, as well as the size property to determine the amount of content. Sets are very useful for eliminating duplication from an array and checking data membership quickly.

Key points

Sets are created with new Set() and only store unique values
Add, delete, check for existence, empty
Size knows the number of elements, not the length
New Set(array) is a quick way to remove duplicates from an array

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