Raw Bytes

As far as the IO system and hard disk are concerned, the program sends a stream of bytes and they are stored on the disk, one after another. There is no concept (at the electronic level) of "int" or "double" or "char". Its all "bytes" to the electronics. The example program did this:

dataOut.writeInt( 0 );
dataOut.writeDouble( 12.45 );

A hex dump shows the 12 bytes. Remember that dumps such as this print two characters to show the pattern in one byte.

The six zeros at the beginning of the line mean the the first byte shown is byte zero of the file. The f's the end of the line show that some bit patterns of the double could also be interpreted as characters.