B4A Library String Functions

Updated: 3/14/2014 - Version 1.05, This new version has 14 new functions/commands. Please report any issues. The new functions/commands are underlined and listed below in the updated docs.

Updated: 9/19/2013 - Version 1.04, Corrected an error in the Mid() function when retrieving the last character.

Updated: 8/28/2013 - Version 1.03, Added code to stop OutOfBounds error on the Mid Function. This would happen when an invalid index was passed to the function. Also corrected a bug that was in the DayOfMonth Function in versions prior to 1.02.

Updated: 4/5/2013 Added new date functions and a simple Encrypt and Decrypt Function. NOTE: A few older Functions were renamed.

StringFunctions use function names that are closer to the VB commands and may help beginners when they start programming in B4A. I wrote them for that reason when I started. These functions use to be in a code module but have now been converted to a Library. This has the new inline syntax and help as you start to type the command.

Requires B4A 2.5 or Higher
Copy the StringFunctions.jar and StringFunctions.xml to the Extra Libraries folder.

Be sure to DIM the Lib object like Below. You can use any variable name in place of sf in the Example below.

Sub Globals
   Dim sf As StringFunctions
   sf.Initialize
End Sub

StringFunctions Version 1.05

• AsciiCodes
  Displays a MessageBox with all Characters and their ASCII codes.
• AddSpaces (HowMany As Int) As String
  Returns a string of spaces. The number returned is set by HowMany.
• At (YourString As String, SearchFor As String))
  Returns the position of the SearchFor within YourString.
• CurrentWeek (MyDate As String) As Int
  Returns the number of the current week, 1-52 from the date passed to MyDate.
• DayOfMonth (MyDate As ) As Int
  Returns the day of the month like 1-31, from the date passed to MyDate.
• Decrypt (YourText As String) As String
  Converts an encrypted string of text to readable format, no key is needed.
• Empty (StringText As String) As Boolean
  Test to see if the string is empty and returns True if it is, otherwise returns False.
• Encrypt (YourText As String) As String
  Converts a string of text to simple encryption, no Key is needed.
• EraseData
  This will erase all data saved with the SaveData function stored in the
  temporary vault.
• FileExist (PathAndFileName As String) As Boolean
  Returns True if the filename passed does exist, otherwise returns False.
  Be sure to include the path like:
  If FileExist("/mnt/sdcard/mydata.dat") Then MsgBox("Yes", "The Answer")
• GetData (Key As Object) As Object
  Gets data from the temporary vault.
  EditText1.Text = SF.GetData("EnteredName")
  The Key is case sensitive.
• InString (YourString As String, SearchFor As String))
  Returns the position of the SearchFor within YourString.
• IsEmpty (StringText As String) As Boolean
  Test to see if the string is empty and returns True if it is, otherwise returns False.
• Left (StringText As String, Length As Long) As String
  Returns the Left portion of a string with the number of characters passed
  in Length.
• Len (StringText As String) As Long
  Returns the length of the string.
• ListToString (YourList As List, Sorted As Boolean, Ascending As Boolean) As String
  Converts a List object to a String.
• ListToStringArray (YourList As List, Sorted As Boolean, Ascending As Boolean) As String()
  Converts a List object to a String Array.
• Lower (StringText As String) As String
  Returns the string converted to Lowercase characters.
• Ltrim (StringText As String) As String
  Returns a new string with the leading spaces removed.
• MB (Message As String)
  Same as MsgBox but only needs one parameter.
• Mid (StringText As String, Start As Int, Length As Int) As String
  Returns the a new String for how ever many characters passed in Length from
  a starting position passed in Start.
  Example:
  Mid("This is a long line of text", 5, 2)
  In this example the function will Return: "is"
• MidExtract (StringText As String, Start As String, EndAt As String) As String
  Used to extract text from a string between to other blocks of text.
  Ans = MidExtract("Dr. Jim Joe Brown", "Jim", "Brown") 'Returns: Joe
  Ans = MidExtract("Dr. Jim [Joe] Brown", "[", "]") 'Returns: Joe
• MidS (StringText As String, StartAt As Int) As String
  Works like the Mid$ function in Visual Basic.
• Month (MyDate As String) As Int
  Returns the number of the current month 1-12 as Int type, from the date passed to MyDate.
• MonthName (MyDate As String) As String
  Returns the Name the current month as a String like January, etc., from the date passed to MyDate.
• NewDate (DatePassed As String, HowManyDays As Int) As String
  Returns a new date adding or subtracting HowManyDays. HowManyDays can be positive or
  negative numbers.
• NumOfDaysBetween (CurrentDate As String, OtherDate As String) As Int
  Returns the numbers of days passed between the two dates passed.
• Pad (Text As String, PadWith As String, Length As Int, Post As Boolean) As String
  Used to pad a string with a selected character. If Post = True the padding will follow
  any text in the string, if Post = False, the padding will be before the text. Length is
  the total length for the padded string. PadWith is the selected character to use for the
  padding.
  SF.Pad("Jimmy Joe", "*", 20, True) 'Returns "Jimmy Joe***********"
• Proper (StringText As String) As String
  Returns the string in proper format.
  Example:
  MyText = "jim joe brown"
  MyText = SF.Proper(Mytext)
  This function will return: "Jim Joe Brown"
• Replicate (mChar As String, Times As Int) As String
  Repeats any character passed, a selected number of Times.
• Right (StringText As String, Length As Long) As String
  Returns the Right portion of a string with the number of characters passed
  in Length.
• RndChrGen (StringLength As Int, CharacterType As Int) As String
  Returns a string of ramdom characters with a length specified by StringLength. CharacterType tells
  the function what type of characters to return.
  CharacterType = 0 for Upper and Lower case
  CharacterType = 1 for Upper case only
  CharacterType = 2 for Lower case only
• Rtrim (StringText As String) As String
  Returns a new string with the trailing spaces removed.
• SaveData (Key As Object, Data As Object)
  Save data passed in a temporary file.
  SF.SaveData("ScreenTitle", MyVar)
  or
  SF.SaveData("EnteredName", EditText1.Text)
• ScrInfo ( As Pect) As Int
  Returns information about the devices screen. You can pass these parameters:
  Pass "W" for Width
  Pass "H" for Height
  Pass "S" for Scale
  Pass "D" for DPI
  Call like: SF.ScrInfo("W")
• SearchDate (Date1 As String, Date2 As String, DateRange As Int) As Boolean
  Returns True if the Date1 and the Date2 are within x Days(DateRange) of each other.
  Pass the dates as Strings.
  Example:
  SearchDate("03/01/2013", "02/15/2013", 30)
• Split (CurrentString As String, Split_At_Delimiter As String) As List
  Returns a LIST of items from the string split at the Delimiter.
  EXAMPLE:
  Dim ANS As List
  ANS = SF.Split("This is a test string.", " ")
• SplitGetWord (CurrentString As String, Split_At_Delimiter As String, GetElement As Int) As String
  Returns just the one element selected with GetElement from the string.
  EXAMPLE:
  ANS = SF.SplitGetWord("This is a test string.", " ", 2)
  In this example the function will Return: "is"
• StrArraySort (StringArray() As String, Ascending As Boolean) As String()
  Used to sort a String Array. Sort will be in Ascending order if Ascending = True.
• StringArrayToList (StringArray() As String, Sorted As Boolean, Ascending As Boolean) As List
  Converts a String Array to a List object.
• StringToList (StringText As String, Sorted As Boolean, Ascending As Boolean) As List
  Convert a String to a List object. This will split the string between words.
• Stuff (CurrentText As String, InsertInString As String, RemoveFromString As String) As String
  Used to replace text in a string with new text.
  Example:
  MyText = "I will tell you that joe is a good friend!"
  MyText = SF.Stuff(MyText, "Joe Brown", "joe")
  This function will return: "I will tell you that Joe Brown is a good friend!"
• Today () As String
  Returns the devices date.
• Trim (Text As String) As String
  Returns a new string with leading and trailing spaces removed.
• Upper (StringText As String) As String
  Returns the string converted to Uppercase characters.
• Val (StringText As String) As Double
  Returns the numerical value of a string. If the string contains now value it returns 0.
• ValidDate (ChkDate As ) As Boolean
  Returns True if the date passed is a Valid date.
• WeekDay (MyDate As String) As String
  Returns the number of the day of the week 1-7 as a String, from the date passed to MyDate.
• WeekName (MyDate As String) As String
  Returns the name of the day of the week like Sunday, Monday, etc., from the date passed to MyDate.
• Year (MyDate As String) As String
  Returns the year of the date passed in MyDate.
  Example:
  SF.Year("01/01/2013") returns "2013"
• getSDCardPath () As String
  Returns external/physical SD Card directory. This function may not return the correct store
  on an Android OS above 4.1. This is due to changes made to the OS system in the newer versions.
  Returns "", if the store can not be read.
• iif (Value1 As String, Value2 As String, Value3 As String) As String
  This is a single line if conditional test. If Value1 is true, Value2 is returned, otherwise
  Value3 will be returned. Works with strings and booleans.
  Example:
  MsgBox(iif("Bob"="Jim", "They are the same", "They are not the same"), "The Answer")
  or
  MyBoolean = iif(FirstTime = True, StartMyService = True, StartMyService = False)

 

[Jost aus Soest]

You could also use the split-function to get the nth word:

Dim s As String
s = "The quick brown fox jumped over the lazy old dog."
word2 = Split(s, " ")(2)  '<-- "brown"
word3 = Split(s, " ")(3)  '<-- "fox"

 

[Jost aus Soest]

getWord

And this is the complete getWord-function:

Sub getWord(str As String, Delimiter As String, n As Int) As String 
  Return Regex.Split(Delimiter, str)(n)
End Sub

 

[margret]

Hello,

I am going to add this function but as [SplitGetWord]. I love the one liners like you wrote above but it returns one word above what you would expect. If you want the 2nd word and you pass a 2, it returns the 3rd word. If you pass a nth selection greater than the array, it throws an exception. I used RBsofts function and modified it with yours to create the [SplitGetWord], if this is ok. The new function is:

Sub SplitGetWord(CurrentString As String, Split_At_Delimiter As String, GetElement As Int) As String
   '*** Original Function by RBSoft modified with suggestions from Jost aus Soest
   Dim t As List
   t = Regex.Split(Split_At_Delimiter, CurrentString)
   rs = iif(GetElement-1 <= t.Size -1, t.Get(GetElement-1), "Invalid Element Selected")
   Return rs
End Sub

 

[Jost aus Soest]

I love the one liners like you wrote above but it returns one word above what you would expect.

I have choosen this counting, because in B4A and Java arrays and string positions are working in the same way: from 0 to n-1.
BTW: Personaly I would prefer start counting from 1.

Of course you can implement this function in your module as you like!

 

[margret]

O.K. Thanks. Any other killer functions you guys can think of I will add. This is one of the great things about B4A and the community, every body working to improve it and make it easier to use!!

Thanks Guys,

Margret

 

[Jost aus Soest]

My Easter present for you, Margret, a reverse function for Split, to join strings:

Sub Join(Strings() As String, Delimiter As String) As String

   Dim i As Int
   Dim sb As StringBuilder

   sb.Initialize
   sb.Append(Strings(0))
   For i = 1 To Strings.Length - 1
      sb.Append(Delimiter).Append(Strings(i))
   Next'i
   Return sb.ToString

End Sub

 

[margret]

Just saw the new function above, thank you and happy Easter a day late! I will add this in!

Thank You,

Margret

 

[BarrySumpter]

Farreakin' Aye man!
Thanks all for the contribution.
Very nice!


Edit:
Anything like:

dt = DateTime.format("YYYY-MM-DD HH:MM:SS", CurrentDate)
I think that's a sql date display format. So may already exist.

or

Have always wanted this:

myExtract = s.ExtractBetween("This is a test", "This ", " test")
returns: "is a"

tia

 

[margret]

Here it is. Copy it to your s. code module:

Sub ExtractBetween(CurrentString As String, FirstWord As String, LastWord As String) As String
   Split_At_Delimiter = Chr(32)
   Dim t As List
   t = Regex.Split(Split_At_Delimiter, CurrentString)
   Dim newstr As String : st = 0 : ed = 0 : newstr = ""
   For l = 0 To t.Size -1
      If t.Get(l) = FirstWord Then
         st = l
      End If
      If t.Get(l) = LastWord Then
         ed = l
      End If   
   Next
   For l = (st +1) To (ed -1)
      newstr = newstr & t.Get(l) & " "
   Next
   Return newstr.Trim
End Sub

 

[BarrySumpter]

This is mine (noobie) with proof of work:

'Activity module
Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'These variables can be accessed from all modules.

End Sub

Sub Globals
    'These global variables will be redeclared each time the activity is created.
    'These variables can only be accessed from this module.

End Sub

Sub Activity_Create(FirstTime As Boolean)

    Dim myVar As String
    
    myVar = "This is a test"
    
    Dim myPos As Int
    
    
    myVar = ExtractBetween("This is a test.  This is only a test. For the next sixty seconds.","only", "sixty")
    myVar = ExtractBetween("<tag1>This is a test.</tag1>  <tag2>This is only a test.</tag2> <tag3>For the next sixty seconds you will be sujected to intense radiation.</tag3>", "<tag1>", "</tag1>")
    myVar = ExtractBetween("<tag1>This is a test.</tag1>  <tag2>This is only a test.</tag2> <tag3>For the next sixty seconds you will be sujected to intense radiation.</tag3>", "<tag2>", "</tag2>")
    myVar = ExtractBetween("<tag1>This is a test.</tag1>  <tag2>This is only a test.</tag2> <tag3>For the next sixty seconds you will be sujected to intense radiation.</tag3>" ,"<tag3>", "</tag3>")
    
    
End Sub

Sub Activity_Resume

End Sub

Sub Activity_Pause (UserClosed As Boolean)

End Sub


Sub ExtractBetween(ExtractFrom As String, StartingWith As String, EndingAt As String) As String
        
        If ExtractFrom.Length = 0 Then
            Return "Nothing to Extract"
        End If
        
        'Sub Mid(Text As String, Start As Int, Length As Int) As String 

        If InStr(ExtractFrom, StartingWith) > -1 Then
        Else
            Return StartingWith & " - not found"
        End If
        
        If InStr(ExtractFrom, EndingAt) > -1 Then
        Else
            Return EndingAt & " - not found"
        End If
        
        Dim myStartPos As Int
        myStartPos = InStr(ExtractFrom, StartingWith)        
        myStartPos = myStartPos + StartingWith.Length + 1
        
        Dim myLength As Int
        myLength = ExtractFrom.Length - myStartPos + 1
                
        Dim myVarWithLeftRemoved As String
        myVarWithLeftRemoved = Mid(ExtractFrom, myStartPos, myLength)
                
        myStartPos = 1        
        myLength = InStr(myVarWithLeftRemoved, EndingAt)
            
        Dim myVarWithRightRemoved As String
        'Sub Left(Text As String, Length As Long)As String
        myVarWithRightRemoved = Left(myVarWithLeftRemoved, myLength )
                
        Dim myVar As String
        myVar = Trim(myVarWithRightRemoved)
        Msgbox ("*" & myVar & "*","")
        
        Return myVar
                
End Sub

Sub InStr(StrVar As String,SearchStr As String)As Long    'Same as At()
    '*** Function by RBSoft
    Dim x As Long
    x = StrVar.IndexOf(SearchStr)
    Return x
End Sub
Sub MB(Message As String)
    Msgbox(Message, "")
End Sub
Sub Left(Text As String, Length As Long)As String 
    If Length>Text.Length Then Length=Text.Length 
    Return Text.SubString2(0, Length)
End Sub
Sub Right(Text As String, Length As Long) As String
    If Length>Text.Length Then Length=Text.Length 
    Return Text.SubString(Text.Length-Length)
End Sub
Sub Mid(Text As String, Start As Int, Length As Int) As String 
    If Len(Text) = 0 Then
        Return ""
    End If    
    Return Text.SubString2(Start-1,Start+Length-1)
End Sub
Sub Len(Text As String) As Long
    Return Text.Length
End Sub
Sub Trim(Text As String) As String
    Return Text.Trim
End Sub

 

[Theera]

Thank you for kind of you.
Theera

 

[pradeepdissa]

Fantastic !!!!


Thanks Margret

:sign0098:

 

[rogeriosca]

Gooooood Job ! Thanks !!

:sign0098:

 

[texwillerx]

instr function

Thank you very much for this excellent work.

Does instr work same as VB version? Should we use

x = StrVar.IndexOf(SearchStr)+1

since indexof returns a zero based result compared to 1 based result for VB

 

[tdocs2]

Fantastic Job

Dear Margret,
As a newbie to B4A but experienced in VB and other languages, I congratulate you on an excellent piece of coding on both examples.
Your style reflects simplicity, accuracy, and succintness - essential skills for an excellent software developer.
Thank you for your contributions.
Sandy

 

[Bens HobbyCorner]

S string already used....

Used your module on existing code, a string named S was used already.
Got an error message on the line

s=s.Replace((CRLF),"")

renamed the string s to r and after that everything is working.

I am a newbie, respect your work. Is this supposed to happen?

Have fun
Ben Zijlstra

 

[fdx12345]

Complete List of Strings in Library

Is there a spot were I can get a complete list of the string commands? Looks like I have to find all of the individual updates to generate a list and I do not want to miss one. The string routines are great! Thank you.

 

[cramcha]

Thank you.

 

[cramcha]

Thanks

Thanks Margret. :sign0098:

 

[margret]

The command list is now on post #1 of this thread and these functions have been updated to a library.

Is there a spot were I can get a complete list of the string commands? Looks like I have to find all of the individual updates to generate a list and I do not want to miss one. The string routines are great! Thank you.