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| 2. 1. 1. 原始类型 |
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Java has eight primitive types of data:
byte, short, int, long, char, float, double, and boolean. |
These can be put in four groups: |
- Integers includes byte, short, int, and long
- Floating-point numbers includes float and double
- Characters includes char, like letters and numbers.
- Boolean includes boolean representing true/false values.
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byte
The smallest integer type
a range from -128 to 127.
useful when working with a stream of data from a network or file.
Byte variables are declared by use of the byte keyword.
byte b, c;
int
The most commonly used integer type
a signed 32-bit type
Ranging from -2,147,483,648 to 2,147,483,647
used to control loops and to index arrays.
the most efficient type
long
a signed 64-bit type
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