Test two objects for inequality.
true
if !(this == that), false otherwise.
Equivalent to x.hashCode
except for boxed numeric types and null
. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For null
returns a hashcode where null.hashCode
throws a NullPointerException
.
a hash value consistent with ==
Test two objects for equality. The expression x == that
is equivalent to if (x eq null) that eq null else x.equals(that)
.
true
if the receiver object is equivalent to the argument; false
otherwise.
Cast the receiver object to be of type T0
.
Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String]
will throw a ClassCastException
at runtime, while the expression List(1).asInstanceOf[List[String]]
will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.
the receiver object.
ClassCastException
if the receiver object is not an instance of the erasure of type T0
.
Compares the receiver object (this
) with the argument object (that
) for equivalence.
Any implementation of this method should be an equivalence relation:
x
of type Any
, x.equals(x)
should return true
.It is symmetric: for any instances x
and y
of type Any
, x.equals(y)
should return true
if and only if y.equals(x)
returns true
.It is transitive: for any instances x
, y
, and z
of type Any
if x.equals(y)
returns true
and y.equals(z)
returns true
, then x.equals(z)
should return true
. If you override this method, you should verify that your implementation remains an equivalence relation. Additionally, when overriding this method it is usually necessary to override hashCode
to ensure that objects which are "equal" (o1.equals(o2)
returns true
) hash to the same scala.Int. (o1.hashCode.equals(o2.hashCode)
).
true
if the receiver object is equivalent to the argument; false
otherwise.
Calculate a hash code value for the object.
The default hashing algorithm is platform dependent.
Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)
) yet not be equal (o1.equals(o2)
returns false
). A degenerate implementation could always return 0
. However, it is required that if two objects are equal (o1.equals(o2)
returns true
) that they have identical hash codes (o1.hashCode.equals(o2.hashCode)
). Therefore, when overriding this method, be sure to verify that the behavior is consistent with the equals
method.
the hash code value for this object.
Test whether the dynamic type of the receiver object is T0
.
Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression 1.isInstanceOf[String]
will return false
, while the expression List(1).isInstanceOf[List[String]]
will return true
. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.
true
if the receiver object is an instance of erasure of type T0
; false
otherwise.
Returns a string representation of the object.
The default representation is platform dependent.
a string representation of the object.
© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.13.0/scala/Nothing.html
Nothing
is - together with scala.Null - at the bottom of Scala's type hierarchy.Nothing
is a subtype of every other type (including scala.Null); there exist no instances of this type. Although typeNothing
is uninhabited, it is nevertheless useful in several ways. For instance, the Scala library defines a value scala.collection.immutable.Nil of typeList[Nothing]
. Because lists are covariant in Scala, this makes scala.collection.immutable.Nil an instance ofList[T]
, for any element of typeT
.Another usage for Nothing is the return type for methods which never return normally. One example is method error in scala.sys, which always throws an exception.