---
title: Collection Implementations
framework: swift
role: collectionGroup
role_heading: API Collection
path: swift/substring/collection-implementations
---

# Collection Implementations

## Topics

### Instance Properties

- [count](swift/substring/count.md)
- [endIndex](swift/substring/endindex.md)
- [first](swift/substring/first.md)
- [indices](swift/substring/indices-swift.property.md)
- [isEmpty](swift/substring/isempty.md)
- [startIndex](swift/substring/startindex.md)
- [underestimatedCount](swift/substring/underestimatedcount.md)

### Instance Methods

- [drop(while:)](swift/substring/drop(while:).md)
- [dropFirst(_:)](swift/substring/dropfirst(_:).md)
- [firstIndex(of:)](swift/substring/firstindex(of:).md)
- [firstIndex(where:)](swift/substring/firstindex(where:).md)
- [formIndex(_:offsetBy:)](swift/substring/formindex(_:offsetby:).md)
- [formIndex(_:offsetBy:limitedBy:)](swift/substring/formindex(_:offsetby:limitedby:).md)
- [formIndex(after:)](swift/substring/formindex(after:).md)
- [index(of:)](swift/substring/index(of:).md)
- [indices(of:)](swift/substring/indices(of:).md)
- [indices(where:)](swift/substring/indices(where:).md)
- [makeIterator()](swift/substring/makeiterator().md)
- [map(_:)](swift/substring/map(_:)-5p6oh.md)
- [popFirst()](swift/substring/popfirst().md)
- [prefix(_:)](swift/substring/prefix(_:).md)
- [prefix(through:)](swift/substring/prefix(through:).md)
- [prefix(upTo:)](swift/substring/prefix(upto:).md)
- [prefix(while:)](swift/substring/prefix(while:).md)
- [randomElement()](swift/substring/randomelement().md)
- [randomElement(using:)](swift/substring/randomelement(using:).md)
- [removeFirst()](swift/substring/removefirst()-5bf95.md)
- [removeFirst(_:)](swift/substring/removefirst(_:)-5qb6j.md)
- [removingSubranges(_:)](swift/substring/removingsubranges(_:).md)
- [split(maxSplits:omittingEmptySubsequences:whereSeparator:)](swift/substring/split(maxsplits:omittingemptysubsequences:whereseparator:).md)
- [split(separator:maxSplits:omittingEmptySubsequences:)](swift/substring/split(separator:maxsplits:omittingemptysubsequences:).md)
- [suffix(from:)](swift/substring/suffix(from:).md)

### Subscripts

- [subscript(_:)](swift/substring/subscript(_:)-2nr4p.md)
- [subscript(_:)](swift/substring/subscript(_:)-392pj.md)
- [subscript(_:)](swift/substring/subscript(_:)-4al8g.md)
- [subscript(_:)](swift/substring/subscript(_:)-4h7r7.md)

### Type Aliases

- [Substring.Index](swift/substring/index.md)
- [Substring.Indices](swift/substring/indices.md)
- [Substring.Iterator](swift/substring/iterator.md)
- [Substring.SubSequence](swift/substring/subsequence.md)