IndexOf string method

[sh]

The IndexOf string method returns the position of the first occurrence
of a character in a string. Is there a method to find the x occurrence
of a character, for example, the 28th occurrence of a character in a string?

Thanks

 

[Cor Ligthert [MVP]]

Shamanda,

I don't know if you are the same as gonzosez where is asked almost the same
question in the second message after yours.

\\\
dim mystring as string = "I contain 70 characters"
if mystring.length > 27 then
dim TwentyEightchar = mystring(27)
end if
///
I hope this helps,

Cor

 

[sh]

Won't that give me what the 27th character is? I'm looking for the
position of the 27th occurrence of some character. For example

MyString = "12x34x56x78x90x12x34x56x78x90x"

So the position of the 7th occurrence of x is 21 (or 20 if zero based)

 

[Chris Dunaway]

\\\
dim mystring as string = "I contain 70 characters"
if mystring.length > 27 then
dim TwentyEightchar = mystring(27)
end if
///

Cor, you've missed what he wants to achieve. He wants to find the 28th
occurrence of a substring within a string.

One possible method (watch for typos):

Public Function FindNthOccurrence(source As String, substring As
String, occurrence As Integer) As Integer
Dim index As Integer = -1
For i As Integer = 0 to occurrence - 1
index = source.IndexOf(substring, index + 1)
If index = -1 Then
Exit For
End If
Next

Return index
End Function

 

[Cor Ligthert [MVP]]

Oh,

That is not to be done simple, you can use repeatly an indexof char, which
is many times quicker than a indexof from a string but you would have to
build code for that something as beneath not really tested see it as pseudo

\\\
dim mychar as char = "x"c
dim start as integer = 0
for x = 0 to 6
if start < mystring.lenth
start = mystring.indexof(start, mychar)
else
exit for
end if
next
///

I hope this helps,

Cor