Data Types

You would like to see the rest of the paper, or know where it came from. Without knowing the context, it is hard to say what MIX means. It could be 1009 in Roman numerals, or it could be the English word "mix" (which itself has several meanings), or it could be the last name of the old-time radio hero Tom Mix. It could be part of a label on a CD: "MTV Dance MIX", or part of a label on a bottle: "BLOODY MARY MIX". Or maybe you are looking at it upside down and it should be "XIW". Of course, it might not be English at all. Without knowing the context, a string of letters has little meaning.

Computer memory stores arbitrary bit patterns. As with a string of letters, the meaning of a string of bits depends on how it is used. The particular scheme that is being used for a particular string of bits is a data type.

A data type —

• Is a scheme for using bits to represent values.
• Values are not just numbers, but any kind of data that a computer can process.
• All values in a computer are represented using one data type or another.

For example:

0000000001100111

is a pattern of 16 bits that might be found somewhere in computer memory. What does it represent?

Without knowing more about how the above pattern is being used, it is impossible to say that it represents. If the pattern is of data type short, then it represents the value 103 (one hundred three.) The type short is one of Java's primitive data types.

0000000000000000