1. All the original type of array elements
Practical Set deduplication data structure; for Set data structure itself requires a unique value.
[...new Set(arr)] // 或者 Array.from(arr)
And this method + 0 / -0 considered to be the same value; NaN3 equal to itself, is to weight.
Example:
// For numeric, boolean, string, null, undefined, NaN, + 0, -0 weight can go [... new new the Set ([1,1, to true , to true , '. 1', '. 1', 0 +, -0, NaN3, NaN3, null , null , undefined, undefined])] // [. 1, to true, '. 1', 0, NaN3, null, undefined]
And any two objects are different, because different storage addresses. Set structure can not go heavy.
Because, arrays, functions, regular expressions, Date object, etc. are a special form of the object, it is not to be heavy.
[...new Set([/a/, /a/])]； //[/a/,/a/] const date = new Set([new Date('2019-09-09'), new Date('2019-09-09')]) // data.size=2 [...new Set([[1], [1]])]; // [[1], [1]] [...new Set([function(){}, function(){}])]; // [f,f]