Any
Class Any is the root of the Scala class hierarchy. Every class in a Scala
execution environment inherits directly or indirectly from this class.
Starting with Scala 2.10 it is possible to directly extend Any using universal traits.
A universal trait is a trait that extends Any, only has defs as members, and does no initialization.
The main use case for universal traits is to allow basic inheritance of methods for value classes. For example,
trait Printable extends Any {
def print(): Unit = println(this)
}
class Wrapper(val underlying: Int) extends AnyVal with Printable
val w = new Wrapper(3)
w.print()See the Value Classes and Universal Traits for more details on the interplay of universal traits and value classes.
Value members
Concrete methods
Test two objects for inequality.
Test two objects for inequality.
- Value Params
- that
the object to compare against this object for equality.
- Returns
trueif !(this == that),falseotherwise.
Equivalent to x.hashCode except for boxed numeric types and null.
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.
- Returns
a hash value consistent with ==
Test two objects for equality.
Test two objects for equality.
The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).
- Value Params
- that
the object to compare against this object for equality.
- Returns
trueif the receiver object is equivalent to the argument;falseotherwise.
Cast the receiver object to be of type T0.
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.
- Returns
the receiver object.
- Throws
- 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.
Compares the receiver object (this) with the argument object (that) for equivalence.
Any implementation of this method should be an equivalence relation:
- It is reflexive: for any instance 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)).
- Value Params
- that
the object to compare against this object for equality.
- Returns
trueif the receiver object is equivalent to the argument;falseotherwise.
Returns the runtime class representation of the object.
Returns the runtime class representation of the object.
- Returns
a class object corresponding to the runtime type of the receiver.
Calculate a hash code value for the object.
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.
- Returns
the hash code value for this object.
Test whether the dynamic type of the receiver object is T0.
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.
- Returns
trueif the receiver object is an instance of erasure of typeT0;falseotherwise.