Why read() method of FileInputStream returns int instead of byte?

[Suresh Rachuru]

Hi All,

Oracle documentation (http://docs.oracle.com/javase/tutorial/essential/io/bytestreams.html) says "Using a int as a return type allows read() to use -1 to indicate that it has reached the end of the stream."

My doubt is why can't be return type is 'byte' as it can hold value -1 ? Any clarification is appreciated. Thanks

[Matthew Brown]

The method needs to be able to read a byte of data (256 possible values) or indicate there are no more values. So it needs to return 257 possibilities. A byte can only hold 256. If it returned a byte, how do you tell the difference between reading a -1 from the file and reaching the end of the stream?