`Reverse`

Reverse( source )

Description

The Reverse function returns in reverse order the items in source, which can be an Array, a Set, or a Page.

Parameters

Parameter Type Definition and Requirements

Parameter	Type	Definition and Requirements
`source`	Array, Set, or Page	The array, set, or page whose items should be reversed.

source

Array, Set, or Page

The array, set, or page whose items should be reversed.

Returns

When source is an Array, an Array containing the items found in source, with their original order reversed.

When source is a Set, a Set containing the items found in source, with their original order reversed.

When source is a Page, a Page of the items found in source, with their original order reversed.

Examples

The following query passes an array to Reverse:

Reverse(['a', 'b', 'c', 1, 2, 3])

[ 3, 2, 1, 'c', 'b', 'a' ]

Query metrics:

bytesIn: 31
bytesOut: 32
computeOps: 1
readOps: 0
writeOps: 0
readBytes: 0
writeBytes: 0
queryTime: 1ms
retries: 0

The following query reverses the set of documents in the Letters collection (established in the Indexing tutorial, and then paginates the set:

Paginate(Reverse(Documents(Collection('Letters'))))

{
  data: [
    Ref(Collection("Letters"), "126"),
    Ref(Collection("Letters"), "125"),
    Ref(Collection("Letters"), "124"),
    Ref(Collection("Letters"), "123"),
    Ref(Collection("Letters"), "122"),
    Ref(Collection("Letters"), "121"),
    Ref(Collection("Letters"), "120"),
    Ref(Collection("Letters"), "119"),
    Ref(Collection("Letters"), "118"),
    Ref(Collection("Letters"), "117"),
    Ref(Collection("Letters"), "116"),
    Ref(Collection("Letters"), "115"),
    Ref(Collection("Letters"), "114"),
    Ref(Collection("Letters"), "113"),
    Ref(Collection("Letters"), "112"),
    Ref(Collection("Letters"), "111"),
    Ref(Collection("Letters"), "110"),
    Ref(Collection("Letters"), "109"),
    Ref(Collection("Letters"), "108"),
    Ref(Collection("Letters"), "107"),
    Ref(Collection("Letters"), "106"),
    Ref(Collection("Letters"), "105"),
    Ref(Collection("Letters"), "104"),
    Ref(Collection("Letters"), "103"),
    Ref(Collection("Letters"), "102"),
    Ref(Collection("Letters"), "101")
  ]
}

Query metrics:

bytesIn: 63
bytesOut: 2,727
computeOps: 1
readOps: 8
writeOps: 0
readBytes: 1,300
writeBytes: 0
queryTime: 13ms
retries: 0

The following query reverses the page of results from paginating the documents in the Letters collection:

Reverse(
  Paginate(
    Documents(Collection('Letters')),
    { size: 3, after: Ref(Collection('Letters'), '104') }
  )
)

{
  before: [ Ref(Collection("Letters"), "104") ],
  after: [ Ref(Collection("Letters"), "107") ],
  data: [
    Ref(Collection("Letters"), "106"),
    Ref(Collection("Letters"), "105"),
    Ref(Collection("Letters"), "104")
  ]
}

Query metrics:

bytesIn: 124
bytesOut: 564
computeOps: 1
readOps: 8
writeOps: 0
readBytes: 1,174
writeBytes: 0
queryTime: 14ms
retries: 0

Notice that Reverse has reversed the order of the results in the page, but has not affected the pagination order.

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Reverse

Description

Parameters

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Examples

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