Java Data type
The data type use for describe things. Java data types are divided into two types: built-in type and extended type.
The built-in type is the basic data type provided by the Java language itself, such as integer, floating point, character, boolean, and so on. The extension type is the Java language according to the basic type of expansion of other types, Java requires all the extension types must be included inside the class definition, which is why Java is the object-oriented programming language reasons. Although different from the pure object-oriented language, such as SmallTalk, Java retains the basic data type, but this is mainly to meet the Java high-efficiency implementation requirements. JRE (Java Runtime Environment) provides a rich and useful extension type for programmers to use, and through the class inheritance mechanism can also be extended as needed.
Java built-in types include the following :
|boolean||boolean, for binary judgment||true , false|
|byte||8-bit signed integer||minimum value -128, maximum 127|
|short||16-bit signed integer||minimum value -32768, maximum 32767|
|int||32-bit signed integer||minimum -2147483648 (-2 31 ), max 2147483647 (2 31 -1)|
|long||64-bit signed integer||- 2 63 ~ (2 63|
|float||32-bit floating point||1.4E-45 ~ 3.4028235E38|
|double||64-bit floating point||4.9E-324 ~ 1.7976931348623157E308|
|char||16-bit Unicode characters||not applicable|