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Binary vs text files

A text file is a file that is properly understood as a sequence of character data (represented using ASCII, Unicode, or some other standard), separated into lines. Typically, when a text file is displayed as a sequence of characters, it is easily human-readable (though perhaps not understandable - for example, the Breakout level file was a text file, but it certainly wouldn't be understandable without some sort of decoder telling which numbers represented what).

A binary file is anything else. A binary file will include some data that is not written using a character-encoding standard - typically, some number would be represented using binary within the file, instead of using the character representation of its various digits (in some base).

Whether you use a binary file or a text file for storing information depends on basically two questions.

Is file size/speed important to me? Binary files tend to be smaller and faster to interpret than text files. For smaller files (less than 1MB), this is rarely a huge issue - things will go smoothly regardless, so you shouldn't worry about it. It's really a concern only for files more than 1MB.
Is portability important to me? Text files tend to transfer to other computers and programs more easily than binary files. Generally, it's easier to understand a text file format than a binary file format, so other programmers can make more sense of it.

For the Breakout lab, file size/speed was unimportant - it was a small file anyway, and you only had to read it once. But portability was a major concern, since each student had to implement the file format themselves. Thus we used a text file.

Next: The DataInputStream class. Up: Binary files. Previous: None.