I want to know use of System.in.read(). for what purpose it is used. In the fillowimg program output is a=65535 . why?

Question

class Program {
public static void main(String[ ] args) {
try{
int a;
a=(char)System.in.read();
System.out.println("a="+a);
}
catch (Exception b)
{
System.out.println""("exception caught ");
}
}

}

Answer 1

Don't cast to char; use int. You're getting a signed integer back, value -1 (byte becomes:65536-1=65535), which indicates end of stream.

Also, read this answer to explain what it does (I'm not going to summarize because anyone can Google this/similar):

http://stackoverflow.com/a/34120618/3981745

Quote relevant to you:
"It returns an int because besides all the possible values of a byte, it also needs to be able to return an extra value to indicate end-of-stream. So, it has to return a type which can express more values than a byte can."

Answer 2

@kirk thanks