Data
Basic skills
Primitive data types
The eight primitive data types
| Type | Bytes | Use |
|---|---|---|
| byte | 1 | Very short integers from -128 to 127. |
| short | 2 | Short integers from -32,768 to 32,767. |
| int | 4 | Integers from -2,147,483,648 to 2,147,483,647. |
| long | 8 | Long integers from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807. |
| float | 4 | Single-precision, floating-point numbers from -3.4E38 to 3.4E38 with up to 7 significant digits. |
| double | 8 | Double-precision, floating-point numbers from -1.7E308 to 1.7E308 with up to 16 significant digits. |
| char | 2 | A single Unicode character that's stored in two bytes. |
| boolean | 1 | A true or false value. |
An overview of the eight primitive data types
- A bit is a binary digit that can have a value of one or zero. A byte is a group of 8 bits.
- Integers are whole numbers.
- Floating-point numbers provide for very large and very small numbers that require decimal positions, but with a limited number of significant digits.
- A single-precision number provides for numbers with up to 7 significant digits. A double-precision number provides for numbers with up to 16 significant digits.
- The Unicode character set provides for over 65,000 characters with two bytes used for each character.
- The older ASCII character set provides for 256 characters with one byte used for each character.
- A boolean data type holds a true or false value.