Android Question Count Special Characters In String

ronovar said:

How can i do that in B4A without using For Loop?

Click to expand...

Dim Name As String= "A,B,C,D,E"
    Dim arrName() As String=Regex.Split(",",Name)
    Log($"Number of commas: ${arrName.Length-1}"$)  'displays 4

ronovar said:

I have string:

B4X:

Dim Name As String

Name = "A,B,C,D,E"

Log(Name.CharactersCount(",")) ' Need To Output 4

How can i do that in B4A without using For Loop? Is there a special library or short version?

I need to cut my string after second "," but need to know how many characters is in string because if i use directly SubString2 and cut after second "," and there is only one "," function will get error code so i need to know exactly how many "," is in the string.

Click to expand...

ronovar said:

I have string:

B4X:

Dim Name As String

Name = "A,B,C,D,E"

Log(Name.CharactersCount(",")) ' Need To Output 4

How can i do that in B4A without using For Loop? Is there a special library or short version?

I need to cut my string after second "," but need to know how many characters is in string because if i use directly SubString2 and cut after second "," and there is only one "," function will get error code so i need to know exactly how many "," is in the string.

Click to expand...

Sub SubStr2(str As String, iStart As Int, iEnd As Int) As String
 If str.Length < iEnd Or str.Length < iStart + 1 Then
  Return ""
 End If
 Return str.SubString2(iStart, iEnd)
End Sub

Mahares said:

For the life of me I do not understand why someone overshadows an answer without giving the person who created the thread a chance to comment, accept or refute the original answer, particularly when they have not tested their code.

Click to expand...

Private lStartTime(10) As Long

Public Sub StartSW(iIndex As Int)
 lStartTime(iIndex) = DateTime.Now
End Sub

Public Sub StopSW(iIndex As Int) As Long
 Return DateTime.Now - lStartTime(iIndex)
End Sub

Sub MakeString2(btByte1 As Byte, btByte2 As Byte, lNum As Long) As String
 
 Dim i As Long
 Dim arrBytes(lNum * 2) As Byte
 
 For i = 0 To lNum - 1 Step 2
  arrBytes(i) = btByte1
 Next
 
 For i = 1 To lNum - 1 Step 2
  arrBytes(i) = btByte2
 Next
 
 Return BC.StringFromBytes(arrBytes, "ASCII")

End Sub

Sub TestCountChar
 
 Dim i As Long
 Dim str As String
 Dim lCount As Long
 Dim arrBytes() As Byte
 
 str = MakeString2(97, 44, 10000000)
 
 General.StartSW(0)
 Dim arrName() As String = Regex.Split(",", str)
 lCount = arrName.Length - 1
 Log("count: " & lCount & "  time: " & General.StopSW(0))
 
 General.StartSW(0)
 arrBytes = str.GetBytes("ASCII")
 lCount = 0
 For i = 0 To arrBytes.Length - 1
  If arrBytes(i) = 44 Then
  lCount = lCount + 1
  End If
 Next
 Log("count: " & lCount & "  time: " & General.StopSW(0))
 
End Sub

Mahares said:

B4X:

Dim Name As String= "A,B,C,D,E"
    Dim arrName() As String=Regex.Split(",",Name)
    Log($"Number of commas: ${arrName.Length-1}"$)  'displays 4

Click to expand...

ronovar said:

Thanks this works very well..i have only two strings that have around from 1 to 38 "," special characters in string and this function works without error.
Thanks.

Click to expand...

alwaysbusy said:

this would be my solution:

B4X:

Dim Name As String = "A,B,C,D,E"
Log(Name.Length - Name.Replace(",", "").Length)

Click to expand...

RB Smissaert said:

but still a lot slower than looping the byte array

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alwaysbusy said:

Sure, but probably a bit of an overkill for the OPs question.

Click to expand...

Sub MakeString3(str As String, lNum As Long) As String
 Dim i As Long
 Dim n As Long
 Dim x As Long
 Dim z As Long
 Dim arrBytes1() As Byte
 arrBytes1 = str.GetBytes("ASCII")
 x = str.Length - 1
 Dim arrBytes2(str.Length * lNum) As Byte
 For i = 1 To lNum
  For n = 0 To x
   arrBytes2(z) = arrBytes1(n)
   z = z + 1
  Next
 Next
 Return BC.StringFromBytes(arrBytes2, "ASCII")
End Sub

ronovar said:

Thanks this works very well..i have only two strings that have around from 1 to 38 "," special characters in string and this function works without error.
Thanks.

Click to expand...