Reference · stzList

DuplicatedItems()

The items that occur more than once in the list.

also: repeated items doubles occur twice duplicates

also written: DupOrigins · Duplicates · Duplications · DuplicatedStrings

Basic examples (2)

Softanza

o1 = new stzList([ 1, "*", 10:12, "B", 2, 1, "*", "A", 3, "*", "B", 10:12, "B" ])
? @@( o1.DuplicatesZ() )

Output

[ [ 1, [ 6 ] ], [ "*", [ 7, 10 ] ], [ [ 10, 11, 12 ], [ 12 ] ], [ "B", [ 11, 13 ] ] ]

run on 2026-10-02 04:22 inside the library at commit 0e72e2e2c; taken from 252_duplicatesz.ring(opens in a new tab)

Softanza

o1 = new stzList([ "A", "B", "A", "A", "C", "D", "B", "E", "a" , "b"])
? @@( o1.DuplicatesCSZ(:CaseSensitive = FALSE) )

Output

[ [ "A", [ 3, 4, 9 ] ], [ "B", [ 7, 10 ] ] ]

run on 2026-10-02 04:22 inside the library at commit 0e72e2e2c; taken from 256_duplicatescsz.ring(opens in a new tab)

Scope (8)

Softanza

o1 = new stzList([ 5, 7, 5, 5, 4, 7, 1 ])
? o1.Duplicates()
? o1.FindDuplicates()

Output

run on 2026-10-02 04:22 inside the library at commit 0e72e2e2c; taken from 258_managing_duplicated_items_check_errros.ring(opens in a new tab)

Softanza

o1 = new stzList([ "*", "4", "*", "3", "4" ])
? o1.NumberOfDuplicates() + NL
? o1.Duplicates()

Output

run on 2026-10-02 04:22 inside the library at commit 0e72e2e2c; taken from 260_numberofduplicates.ring(opens in a new tab)

Softanza

aList = [ "A", "B", 1, "A", "A", 1, "C", 1:2, "D", "B", "E", '"1"', 1:2 ]
o1 = new stzList(aList)
? @@( o1.DuplicatesZ() )
? ""
? @@( o1.DuplicatesXTZ() )

Output

[ [ "A", [ 4, 5 ] ], [ "B", [ 10 ] ], [ 1, [ 6 ] ], [ [ 1, 2 ], [ 13 ] ] ]

[ [ "A", [ 1, 4, 5 ] ], [ "B", [ 2, 10 ] ], [ 1, [ 3, 6 ] ], [ "C", [ 7 ] ], [ [ 1, 2 ], [ 8, 13 ] ], [ "D", [ 9 ] ], [ "E", [ 11 ] ], [ '"1"', [ 12 ] ] ]

run on 2026-10-02 04:22 inside the library at commit 0e72e2e2c; taken from 253_duplicatesz.ring(opens in a new tab)

Softanza

o1 = new stzList([ "A", "B", "B", "B", "b", "C", "B", "C", "C", "c", "A" ])
? o1.DupOrigins() # Same As Duplicates()
? o1.FindDupOrigins()
o1.RemoveDupOrigins()
? @@( o1.Content() )

Output

A
B
C

1
2
6

[ "B", "B", "b", "B", "C", "C", "c", "A" ]

run on 2026-10-02 04:22 inside the library at commit 0e72e2e2c; taken from 140_duporigins.ring(opens in a new tab)

Softanza

o1 = new stzList([ "a", "ab", "b", 1:3, "a", "ab", "abc", "b", "bc", 1:3,"c" ])
? o1.FindDuplicates()
? @@( o1.ItemsAtPositions( o1.FindDuplicates() ) )
? @@( o1.Duplicates() ) + NL
? @@( o1.DuplicatesZ() )

Output

5
6
8
10

[ "a", "ab", "b", [ 1, 2, 3 ] ]
[ "a", "ab", "b", [ 1, 2, 3 ] ]

[ [ "a", [ 5 ] ], [ "ab", [ 6 ] ], [ "b", [ 8 ] ], [ [ 1, 2, 3 ], [ 10 ] ] ]

run on 2026-10-02 04:22 inside the library at commit 0e72e2e2c; taken from 266_findduplicates.ring(opens in a new tab)

Softanza

o1 = new stzList([ 5, 7, 5, 5, 4, 7 ])
? o1.ContainsDuplicates()
? o1.HowManyDuplicates()
? @@( o1.FindDuplicates() )
? @@( o1.DuplicatesZ() ) # Or DuplicatesAndTheirPositions()
o1.RemoveDuplicates()
? @@( o1.Content() )

Output

1
3
[ 3, 4, 6 ]
[ [ 5, [ 3, 4 ] ], [ 7, [ 6 ] ] ]
[ 5, 7, 4 ]

run on 2026-10-02 04:22 inside the library at commit 0e72e2e2c; taken from 243_containsduplicates.ring(opens in a new tab)

Softanza

o1 = new stzList([ "_", "ONE", "_", "_", "TWO", "_", "THREE", "*", "*" ])
? o1.ContainsDuplicates()
? @@( o1.FindDuplicates() )
? @@( o1.Duplicates() )
? @@( o1.DuplicatesZ() ) # Or DuplicatesAndTheirPositions()
o1.RemoveDuplicates()
? @@( o1.Content() )

Output

1
[ 3, 4, 6, 9 ]
[ "_", "*" ]
[ [ "_", [ 3, 4, 6 ] ], [ "*", [ 9 ] ] ]
[ "_", "ONE", "TWO", "THREE", "*" ]

run on 2026-10-02 04:22 inside the library at commit 0e72e2e2c; taken from 234_containsduplicates.ring(opens in a new tab)

Softanza

o1 = new stzList([ "tunis", 1:3, 1:3, "gafsa", "tunis", "tunis", 1:3, "gabes", "tunis", "regueb", "regueb" ])
o1.Reverse()
? @@( o1.Content() ) + NL
? o1.NumberOfDuplicates()
? o1.NumberOfDuplicatesOf("tunis") + NL	# Or NumberOfOccurrence("tunis")
? @@( o1.DuplicatedItems() ) + NL
? @@( o1.DuplicatesRemoved() )

Output

[ "regueb", "regueb", "tunis", "gabes", [ 1, 2, 3 ], "tunis", "tunis", "gafsa", [ 1, 2, 3 ], [ 1, 2, 3 ], "tunis" ]

6
4

[ "regueb", "tunis", [ 1, 2, 3 ] ]

[ "regueb", "tunis", "gabes", [ 1, 2, 3 ], "gafsa" ]

run on 2026-10-02 04:23 inside the library at commit 0e72e2e2c; taken from 588_reverse.ring(opens in a new tab)

and 2 more in the tests

The extensions of this method

Each extension, and whether it exists for this method; an extension that exists combines with the others (FindSTCS).

Extension

Exists

What it adds · The names

does what the method does, then returns the object, so the call can be chained

chains on the next, more specific type of object (the Q ladder)

QQQ

chains on the most specific type of object (the Q ladder)

QRT

returns the result as an object of the requested type

yes

takes a case-sensitivity flag · DuplicatesCS, DuplicatedItemsCS, DuplicatedStringsCS, DuplicatesCSZ and 1 more

takes the position to start from (StartingAt)

takes bounds that are included (IncludingBounds)

yes

the extended form: more parameters than the base method · DuplicatesXTZ, DuplicatesCSXTZ

XTT

yet another extension: a further extended form, after XT

yes

includes the position in what it returns · DuplicatesZ, DuplicationsZ, DuplicatedItemsZ, DuplicatesCSZ and 2 more

returns positions as sections, [start, end]

selects by a condition

selects by a condition, with the expressive keywords (@NextItem, @PreviousItem...)

takes a direction, forward or backward (Directional)

takes a function (the condition or the update is given as a function); the forms document also uses F for the future form, which defers the action

Many

works on a collection of items instead of one (the plural form)

Except

takes exceptions, what to leave out (the exceptional form)

returns the result without duplication

Every example is a test file of the library, run inside the library for this page; only those whose output kept every promise their file wrote are shown.

DuplicatedItems()

Basic examples (2)

Scope (8)

The extensions of this method

See also