Question regardig indexof(string, int32, int32)

  • Thread starter Thread starter Jorge Rojas
  • Start date Start date
J

Jorge Rojas

I have a question. I'm dealing with indexof and I got a behaviour I never
expected...

From documentation,

public int IndexOf (
string value,
int startIndex,
int count
)

should return the "count" occurrence of search after start.

Am I wrong?

The code (c#):

/******/
string aSearch;
int aPos;
aSearch = "This is a dumb test, a simple test for testing a test
I want to test";
aPos = aSearch.IndexOf("test", 2, 1);
/******/

I got aPos= -1 ??? How???

Another:
/******/
aSearch = "This is a dumb test, a simple test for testing a test
I want to test";
aPos = aSearch.IndexOf("test", 1, 1);
/******/

I got aPos = -1 again...

The only one that works is aString.IndexOf(search, index) Any ideas? What I
am doing wrong?
 
Jorge said:
I have a question. I'm dealing with indexof and I got a behaviour I
never expected...

From documentation,

public int IndexOf (
string value,
int startIndex,
int count
)

should return the "count" occurrence of search after start.
Click to expand...

Where did you get that idea?
Am I wrong?
Click to expand...

Yes.

The count argument determines how many characters in the string is
searched. It's searching in the string that you would get by using
aSearch.Substring(startIndex, count).

Or as the documentation says:

"count - The number of character positions to examine."
The code (c#):

/******/
string aSearch;
int aPos;
aSearch = "This is a dumb test, a simple test for testing a
test I want to test";
aPos = aSearch.IndexOf("test", 2, 1);
/******/

I got aPos= -1 ??? How???
Click to expand...

Because you are looking in a part of the string that is only one
character long. You can hardly find a four character string inside a one
character string.
Another:
/******/
aSearch = "This is a dumb test, a simple test for testing a
test I want to test";
aPos = aSearch.IndexOf("test", 1, 1);
/******/

I got aPos = -1 again...

The only one that works is aString.IndexOf(search, index) Any ideas?
What I am doing wrong?
Click to expand...

Not reading the documentation properly... ;)
 
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