StringArray B4X (B4A / B4J) Reference Documentation

ChilkatStringArray

Current Version: 11.6.0

Chilkat.StringArray

Manage an ordered collection of strings, with StringTable recommended for new code.

Chilkat.StringArray is an ordered string-collection class that can append, prepend, insert, replace, remove, pop, and retrieve strings by index. It can load one string per line from files or in-memory text, save the collection back to text or files, enforce uniqueness, trim incoming values, normalize line endings, search by exact value or wildcard pattern, sort entries, split text into entries, serialize and restore the collection, and perform set-style operations such as union and subtraction.

Recommendation: For new development, prefer Chilkat.StringTable instead of Chilkat.StringArray. StringTable provides a simpler, faster, and more memory-efficient way to manage ordered lists of strings. Use StringArray primarily when maintaining existing code or when a specific API or older example already uses it.

Ordered string collection

Store strings in an internal ordered collection and retrieve them by zero-based index using GetString, StrAt, or LastString.

Add and modify entries

Append, prepend, insert, replace, remove, clear, or pop strings as the collection changes.

Load and save text

Load one string per line from files or text, and save the collection back to files or a single line-delimited string.

Charset-aware file I/O

Use charset-specific load and save methods when working with UTF-8, UTF-16, or other non-ANSI text encodings.

Search, match, and sort

Check for exact strings, find values from a starting index, match wildcard patterns, and sort ascending or descending.

Serialize and combine

Serialize the collection for later restoration, split text into entries, and combine or subtract collections with set-style operations.

Common pattern: Create a StringArray, optionally set Trim, Crlf, or Unique, then append strings directly or load them from a file or text block. Search, sort, split, remove, union, or subtract entries as needed, then save the result with SaveToText, SaveToFile, or SaveToFile2. For new code that only needs an ordered list of strings, use Chilkat.StringTable instead.
Naming note: Although the class name contains Array, Chilkat.StringArray is a Chilkat object that manages an ordered string collection. It should not be confused with a native array type in a programming language.

Declare / Initialize / Dispose

Sub Process_Globals
    Private obj As ChilkatStringArray
End Sub

' Call Initialize before first use -- typically in AppStart (B4J)
' or Activity_Create (B4A):
obj.Initialize                ' classes without events
obj.Initialize("evt")        ' classes with events: "evt" becomes the
                              ' prefix of event Subs such as evt_PercentDone
Initialize  /  Initialize (EventName As String)

Creates the underlying native Chilkat object. Classes that support events take an EventName argument: it becomes the prefix of the event Subs (<EventName>_AbortCheck, <EventName>_PercentDone, <EventName>_ProgressInfo); classes without events take no arguments. The native Chilkat library loads automatically on the first Initialize — from the APK on Android, or extracted from ChilkatB4J.jar on Windows/Linux/macOS.

IsInitialized As Boolean

True if Initialize has been called and the native object exists.

Dispose

Explicitly frees the underlying native object. Calling Dispose is optional — every ChilkatStringArray is also freed automatically when garbage-collected — but is recommended for long-lived objects holding sockets, sessions, or large buffers. A disposed object can be re-Initialized.

Properties

Count
' read-only
Count As Int

The number of strings contained within the object's internal array (i.e. ordered collection).

Important: This is an object that contains a collection of strings. Although the class/object name includes the word Array, it should not be confused with an array in the sense of the primitive array type used in a given programming language.

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Crlf
' read/write
Crlf As Boolean

If True, strings are always automatically converted to use CRLF line endings. If False, strings are automatically converted to use bare LF line endings.

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DebugLogFilePath
' read/write
DebugLogFilePath As String

If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.

Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.

Possible causes of hangs include:

  • A timeout property set to 0, indicating an infinite timeout.
  • A hang occurring within an event callback in the application code.
  • An internal bug in the Chilkat code causing the hang.

More Information and Examples
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LastErrorHtml
' read-only
LastErrorHtml As String

Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorText
' read-only
LastErrorText As String

Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorXml
' read-only
LastErrorXml As String

Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastMethodSuccess
' read/write
LastMethodSuccess As Boolean

Indicates the success or failure of the most recent method call: True means success, False means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.

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Length
' read-only
Length As Int

The number of strings contained within the internal collection. (Identical to the Count property.)

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Trim
' read/write
Trim As Boolean

If True, whitespace, including carriage-returns and linefeeds, are automatically removed from the beginning and end of a string when added to the collection.

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Unique
' read/write
Unique As Boolean

If True, then duplicates are not allowed. When an attempt is made to insert a string that already exists, the duplicate insertion is silently suppressed and no error is returned. The default value is False.

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VerboseLogging
' read/write
VerboseLogging As Boolean

If set to True, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is False. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
' read-only
Version As String

Version of the component/library, such as "10.1.0"

More Information and Examples
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Methods

Append
Append (str As String) As Boolean

Appends a string to the end of the internal ordered collection.

Returns True for success, False for failure.

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AppendSerialized
AppendSerialized (encodedStr As String) As Boolean

Appends multiple strings to the end of the internal ordered collection. The encodedStr is what is returned from the Serialize method (see below).

Returns True for success, False for failure.

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Clear
Clear

Remove all strings from the internal collection.

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Contains
Contains (str As String) As Boolean

Returns True if the string is present in the internal collection. The string comparisons are case sensitive.

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Find
Find (findStr As String, startIndex As Int) As Int

Finds the index of the first string equal to findStr. The search begins at startIndex. If the string is not found, -1 is returned. The first string in the array is at index 0.

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FindFirstMatch
FindFirstMatch (matchPattern As String, startIndex As Int) As Int

Finds the first string that matches the matchPattern. The search begins at startIndex. If the string is not found, -1 is returned. The first string in the array is at index 0.

The matchPattern may contain zero or more asterisk chars, each of which matches 0 or more of any character.

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GetString
GetString (index As Int) As String

Returns the string at an indexed location within the internal collection. The first string is located at index 0.

Returns Null on failure

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GetStringLen
GetStringLen (index As Int) As Int

Returns Nth string's length, in characters. The first string is located at index 0.

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InsertAt
InsertAt (index As Int, str As String)

Inserts a string into the internal collection at a specified index. Using index 0 will insert at the beginning.

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LastString
LastString As String

Returns the last string in the internal collection.

Returns Null on failure

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LoadFromFile
LoadFromFile (path As String) As Boolean

Loads strings from a file (one per line) into the internal collection. It is assumed the file contains ANSI strings. To load from a file containing non-ANSI strings (such as utf-8), call LoadFromFile2 instead.

Note: This method appends the strings in path to the existing collection of strings contained in this object.

Returns True for success, False for failure.

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LoadFromFile2
LoadFromFile2 (path As String, charset As String) As Boolean

Loads strings from a file (one per line) into the internal collection. The charset specifies the character encoding (such as utf-8) of the strings contained in the file.

Note: This method appends the strings in path to the existing collection of strings contained in this object.

Returns True for success, False for failure.

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LoadFromText
LoadFromText (str As String)

Loads strings from an in-memory string (one per line) into the internal collection.

Note: This method appends the strings in str to the existing collection of strings contained in this object.

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Pop
Pop As String

Returns the last string and removes it from the internal collection.

Returns Null on failure

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Prepend
Prepend (str As String)

Adds a string to the beginning of the internal collection.

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Remove
Remove (str As String)

Removes all strings equal to the string argument from the internal collection.

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RemoveAt
RemoveAt (index As Int) As Boolean

Removes the string at a particular index.

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ReplaceAt
ReplaceAt (index As Int, str As String)
Introduced in version 9.5.0.52

Replaces the string at a specified index.

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SaveNthToFile
SaveNthToFile (index As Int, saveToPath As String) As Boolean

Saves the Nth string in the collection to a file.

Returns True for success, False for failure.

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SaveToFile
SaveToFile (path As String) As Boolean

Saves the collection of strings to a file, one string per line. Strings are saved using the ANSI charset. (Call SaveToFile2 to specify a charset, such as utf-8)

Returns True for success, False for failure.

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SaveToFile2
SaveToFile2 (saveToPath As String, charset As String) As Boolean

Saves the collection of strings to a file, one string per line. Strings are saved using the specified charset.

Returns True for success, False for failure.

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SaveToText
SaveToText As String

Writes the collection of strings to a single string, one per line (separated by CRLF line endings).

Returns Null on failure

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Serialize
Serialize As String

Returns an string which is an encoded representation of all the strings in the collection. The string collection can be re-created by calling the AppendSerialized method.

Returns Null on failure

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Sort
Sort (ascending As Boolean)

Sorts the strings in the collection in ascending or descending order. To sort in ascending order, set ascending to True, otherwise set ascending equal to False.

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SplitAndAppend
SplitAndAppend (str As String, boundary As String)

Splits a string at a character or substring boundary and adds each resulting string to the internal collection.

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StrAt
StrAt (index As Int) As String

Returns the string at a specific index.

Returns Null on failure

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Subtract
Subtract (stringArrayObj As ChilkatStringArray)

Subtracts the strings contained within stringArrayObj from the caller's internal collection.

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Union
Union (stringArrayObj As ChilkatStringArray)

Performs the union set-operator. The result is that the caller will have a string collection that is the union of itself and stringArrayObj.

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