Standard out is a buffered stream, it is not guaranteed to flush unless a newline is put in, the stream is closed, or the program exits normally. If the program exits abnormally, it is possible for the stream to not flush. Standard out is line buffered, which is why a newline will flush it. There are buffers that will not flush with a newline.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…