what is meaning of “readlimit” parameter at mark method in java?

Question

BufferedInputStream.mark(int readlimit) 

I read java doc but I don't understand when we use this parameter " readlimit " in this code, I don't understand what's different between mark(1) or mark(100)

public static void main(String[] args) throws Exception {
String s="123456789ABCDEFGHIJKLMNOPQRSDVWXYZ";
byte byteArray[]=s.getBytes();
ByteArrayInputStream BArrayIS=new ByteArrayInputStream(byteArray);
BufferedInputStream BIS=new BufferedInputStream(BArrayIS);
BIS.mark(1);
System.out.println(BIS.read());
}

Answer 1

It has no effect because BufferedInputStream.mark method effects `` which is used in reset method that you don't use.

Repositions this stream to the position at the time the mark method