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.
B4X:
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)
 

Attachments

  • StringFunctions 1.0.zip
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  • StringFunctions 1.01.zip
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  • StringFunctions 1.03.zip
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  • StringFunctions 1.04.zip
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  • StringFunctions 1.05.zip
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Last edited:

Rusty

Well-Known Member
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Longtime User
Hi Margaret, good work!
Can the Split function split a string based upon the existence of another STRING?

B4X:
dim s() as list = x.Split("Now is the time", "the")
results in an array that contains:
B4X:
s.get(0) = "Now is "
s.get(1) = " time"
Thanks in advance,
Rusty
 
Last edited:

Rusty

Well-Known Member
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Longtime User
Thanks Margaret,
I did try it and, no, it doesn't handle it...
I had to write my own function to do so. I was hoping :)
Regards,
Rsuty
 

peggjones

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Functions not Working

Can anyone help me? I've added stringfunctions to my project but when I try to use a function (I've been trying with "Mid") the program won't compile. Is there anything else I need to do?

Many Thanks.
 

peggjones

Active Member
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Longtime User
Problem with Stringfunction

I have added stringfunctions to my project. Yet when I try to use a function from it it is highlighted in red and the program won't compile. Is there anything else I need to do to enable stringfunctions.

Many Thanks
 

BvdB

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I have added stringfunctions to my project. Yet when I try to use a function from it it is highlighted in red and the program won't compile. Is there anything else I need to do to enable stringfunctions.

Many Thanks

I'm also new to B4A, but experienced with VB, please excuse me if I ask stupid questions in the beginning :sign0161:

I have the same experience and also get a compiler error.

I added the and selected the StringFunctions libraries as described in #1, and selected it for the project, but when I use the IsEmpty() function, I get the error: Undeclared variable 'isempty' is used before it was assigned any value.

Is there anything else I need to add or include somewhere to use the StringFunctions library?

Any help will be appreciated.
 

ValDog

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I am seeing the same problem, and I have checked StringFunctions on the IDE...
 

BvdB

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Have you put a check on the checkbox next to the library name on the IDE?

Yes, I added version 1.01 to the library and checked (marked) it in the library.
Attached is a screenshot, hopefully it provides sufficient info to assist me.

Thanks
 

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NJDude

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Yes, I added version 1.01 to the library and checked (marked) it in the library.
Attached is a screenshot, hopefully it provides sufficient info to assist me.

Thanks

Well my friend, is not only adding and referencing the library, you have to INITIALIZE it too, you are missing something like:
B4X:
Dim sf As StringFunctions

...

If sf.IsEmpty(txtNumber) then ...
 

MattC

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I just know this is going to be a stupid question but I cannot figure this out so I'll ask anyway.
I have everything working fine in the main activity.
I'm now trying to use the stringfunctions in a code module and it looks like the only method that works is to dim and init the stringfunctions in every sub. I'd have expected to do this once only in a code module but using globals and process globals produced errors.
Am I missing something?
 

klaus

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Sure you can!
You can define Dim sf As StringFunctions in any module in ProcessGlobals.
But to call sf from another module you must add the module name as a prefix.
Example: you Dim sf As StringFunctions in a code module named Test.
Then you can use sf in any other module with Test.sf.xxx like any other process global variable.

Best regards.
 

MattC

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Longtime User
Thank Klaus,
That's what I expected but when I try that I get this in the compile and debug window:
Compiling generated Java code. Error
B4A line: 9
sf.Initialize
javac 1.7.0_21
src\anywheresoftware\b4a\samples\httputils2\mf.java:149: error: cannot find symbol
_sf._vvv1((_ba.processBA == null ? _ba : _ba.processBA));
^
symbol: variable _ba
location: class mf
 

MattC

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Longtime User
Are you calling sf.Initialize from Sub Process_Globals?

That's what gets me the java error above.
From Globals it doesn't get dimmed or initialised at all.
I've just noticed under another code module that I cannot dim from globals there either.
What should I be doing?
Thanks for the help.
 
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