String


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String

Last updated at 9:57 am UTC on 19 July 2022

 ArrayedCollection subclass: #String
 	instanceVariableNames: ''
 	classVariableNames: 'AsciiOrder CSMacroCharacters CaseInsensitiveOrder CaseSensitiveOrder CrLfExchangeTable FormatCharacterSet HtmlEntities LowercasingTable Tokenish UppercasingTable'
 	poolDictionaries: ''
 	category: 'Collections-Strings'

 String subclasses {ByteString . WideString . Symbol}

String class comment

(Squeak 5.0)
A String is an indexed collection of Characters. Class String provides the abstract super class for ByteString (that represents an array of 8-bit Characters) and WideString (that represents an array of 32-bit characters). In the similar manner of LargeInteger and SmallInteger, those subclasses are chosen accordingly for a string; namely as long as the system can figure out so, the String is used to represent the given string.

Strings support a vast array of useful methods, which can best be learned by browsing and trying out examples as you find them in the code.

Here are a few useful methods to look at...

	String match:
	String contractTo:

String also inherits many useful methods from its hierarchy, such as

    SequenceableCollection ,

    SequenceableCollection copyReplaceAll:with:

is used to do String substitution.

Strings are kept as Unicode code points arrays, and converted to encoded forms when entering/exiting the system.

Pharo/Squeak Strings keep data in UTF32 encoding form, where 1 codepoint = 1 code unit, dynamically switched between Latin1 (ByteStrings) and UTF32 (WideStrings) encoding schemes as needed.

Subclasses are:

The distinction between ByteString and WideString is a mostly invisible implementation detail.

See String equivalence (Unicode)

Some common instance methods (too many to list but here are a few)

accessing
- at:, at: put:
- findString:, findAnySubStr: startingAt:, findCloseParenthesisFor:
- tabDelimitedFieldsDo;, indexOf:
comparing
- <, >, =, ≤, ≥, compare:
- beginsWith:, endsWith:, endsWithAnyOf:
converting
- asMorph, asDate, asHtml, asHex, asParagraph, asUpperCase
- subStrings, romanNumber, capitalized, asUrl
printing
- encodeDoublingQuoteOn:, printOn:, storeOn:

Some common class methods

instance creation
- cr, crlf, tab, lf (create strings of non-enterable characters)
- fromString:, readFrom:
initialize
- initializeHtmlEntities

Examples

 "'abcd' capitalized" -> 'Abcd'
 "'abcd' endsWithAnyOf: #('d', 'D')" -> true
 "('abcd' at:2)." -> $b
 "'abcd' at: 2 put: $3" -> $3 (returns the put: argument)
 "c _ 'abcd'. c byteAt:2 put:35. c." -> 'a#cd' 
 "('a,b c,d' findTokens: (String with: Character cr))
       collect: [:aLine | aLine findTokens: ',']

Generated documentation?

The objects of the class String are collections of characters which have specific methods for dealing with them.
(Squeak 3.3a-4664)
String selectors size is 173
String allSelectors size is 730

ProtoObject #()

Object #()

Collection #()

Text #()

ArrayedCollection #()

String #()

Symbol #()

Hints and tips

Simple string pattern matching! Do print it on each line,
see method
String>>match: for more details."
'abc*' match: 'abcdef' 'ab#de#' match: 'abcdef' '*def' match: 'abcdef'