-
sealed final
class
AnyVal
extends Any
Class AnyVal is the root class of all
value types.
AnyVal has a fixed number subclasses, which
describe values which are not implemented as objects in the
underlying host system.
Classes Double,
Float,
Long,
Int,
Char,
Short, and
Byte are together called
numeric value types.
Classes Byte,
Short, or
Char
are called subrange types. Subrange types, as well as
Int and
Long are called
integer types, whereas
Float and
Double are called
floating point types.
- Direct Known Subclasses:
- Boolean, Byte, Char, Double, Long, Float, Int, Short, Unit
The type Int names the class Int in the package
scala. Values of this class are implemented just like Java's
int values. In fact, Scala treats int as an alias for
scala.Int. More generally, all of Java's primitive types are
defined as aliases for classes in the scala package. For example, if you
type boolean in a Scala program, the type you'll actually get is
scala.Boolean. Or if you type float, you'll get
scala.Float. When you compile your Scala code to Java bytecodes,
however, Scala will compile these types to Java's primitive types where possible
to get the performance benefits of Java's primitive types.
- AnyVal 是 Scala 裡每個內建值類型的父類別。
- AnyVal 有固定數量的子類別, 用以描述值且不能被實例化成物件。
有九個這樣的值類：Byte，Short，Char，Int，Long，Float，Double，Boolean和Unit。其中的前八個對應到Java的 原始類型，它們的值在運行時表示成Java的原始值。Scala裡這些類的實例都寫成文本。例如，42是Int的實例，'x'是Char的實例，false是Boolean的實例。 你不能使用new 創造這些類的實例。這一點被「小伎倆」，值類都被定義為即是抽象的又是final的，強制貫徹。 -
abstract final
class
Int
extends AnyVal
Class Int belongs to the value
classes whose instances are not represented as objects by the
underlying host system. There is an implicit conversion from
instances of Int to instances of
runtime.RichInt which
provides useful non-primitive operations. All value classes inherit
from class AnyVal.
Values MAX_INT and MIN_INT
are in defined in object scala.Math.
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