scala.math

# Ordered

#### trait Ordered[A] extends Comparable[A]

A trait for data that have a single, natural ordering. See scala.math.Ordering before using this trait for more information about whether to use scala.math.Ordering instead.

Classes that implement this trait can be sorted with scala.util.Sorting and can be compared with standard comparison operators (e.g. > and <).

Ordered should be used for data with a single, natural ordering (like integers) while Ordering allows for multiple ordering implementations. An Ordering instance will be implicitly created if necessary.

scala.math.Ordering is an alternative to this trait that allows multiple orderings to be defined for the same type.

scala.math.PartiallyOrdered is an alternative to this trait for partially ordered data.

For example, create a simple class that implements `Ordered` and then sort it with scala.util.Sorting:

    case class OrderedClass(n:Int) extends Ordered[OrderedClass] {
    	def compare(that: OrderedClass) =  this.n - that.n
    }

    val x = Array(OrderedClass(1), OrderedClass(5), OrderedClass(3))
    scala.util.Sorting.quickSort(x)
    x

It is important that the `equals` method for an instance of `Ordered[A]` be consistent with the compare method. However, due to limitations inherent in the type erasure semantics, there is no reasonable way to provide a default implementation of equality for instances of `Ordered[A]`. Therefore, if you need to be able to use equality on an instance of `Ordered[A]` you must provide it yourself either when inheriting or instantiating.

It is important that the `hashCode` method for an instance of `Ordered[A]` be consistent with the `compare` method. However, it is not possible to provide a sensible default implementation. Therefore, if you need to be able compute the hash of an instance of `Ordered[A]` you must provide it yourself either when inheriting or instantiating.

Version

  1.1, 2006-07-24

See also

  scala.math.Ordering, scala.math.PartiallyOrdered

Linear Supertypes
Comparable[A], Any
Known Subclasses
Deadline, Duration, FiniteDuration, FractionalProxy, Infinite, IntegralProxy, OrderedProxy, RichBoolean, RichByte, RichChar, RichDouble, RichFloat, RichInt, RichLong, RichShort, ScalaNumberProxy, ScalaWholeNumberProxy, StringBuilder, StringLike, StringOps, Val, Value, WrappedString
Type Hierarchy Learn more about scaladoc diagrams
Ordering

1. Alphabetic
2. By inheritance

Inherited

1. Ordered
2. Comparable
3. Any

Implicitly

1. by orderingToOrdered
2. by any2stringadd
3. by StringFormat
4. by Ensuring
5. by ArrowAssoc

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### Abstract Value Members

1. #### abstract def compare(that: A): Int

   Result of comparing `this` with operand `that`.

   Result of comparing `this` with operand `that`.

   Implement this method to determine how instances of A will be sorted.

   Returns `x` where:

   - `x < 0` when `this < that`
   - `x == 0` when `this == that`
   - `x > 0` when `this > that`

2. #### abstract def getClass(): Class[_]

   Definition Classes
     Any

### Concrete Value Members

1. #### final def !=(arg0: Any): Boolean

   Definition Classes
     Any

2. #### final def ##(): Int

   Definition Classes
     Any

3. #### def +(other: String): String

   Implicit information
     This member is added by an implicit conversion from Ordered[A] to any2stringadd[Ordered[A]] performed by method any2stringadd in scala.Predef.
   Definition Classes
     any2stringadd

4. #### def ->[B](y: B): (Ordered[A], B)

   Implicit information
     This member is added by an implicit conversion from Ordered[A] to ArrowAssoc[Ordered[A]] performed by method ArrowAssoc in scala.Predef.
   Definition Classes
     ArrowAssoc
   Annotations
     @inline()

5. #### def <(that: A): Boolean

   Returns true if `this` is less than `that`

6. #### def <=(that: A): Boolean

   Returns true if `this` is less than or equal to `that`.

7. #### final def ==(arg0: Any): Boolean

   Definition Classes
     Any

8. #### def >(that: A): Boolean

   Returns true if `this` is greater than `that`.

9. #### def >=(that: A): Boolean

   Returns true if `this` is greater than or equal to `that`.

10. #### final def asInstanceOf[T0]: T0

    Definition Classes
      Any

11. #### def compareTo(that: A): Int

    Result of comparing `this` with operand `that`.

    Result of comparing `this` with operand `that`.

    Definition Classes
      Ordered → Comparable

12. #### def ensuring(cond: (Ordered[A]) ⇒ Boolean, msg: ⇒ Any): Ordered[A]

    Implicit information
      This member is added by an implicit conversion from Ordered[A] to Ensuring[Ordered[A]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring

13. #### def ensuring(cond: (Ordered[A]) ⇒ Boolean): Ordered[A]

    Implicit information
      This member is added by an implicit conversion from Ordered[A] to Ensuring[Ordered[A]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring

14. #### def ensuring(cond: Boolean, msg: ⇒ Any): Ordered[A]

    Implicit information
      This member is added by an implicit conversion from Ordered[A] to Ensuring[Ordered[A]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring

15. #### def ensuring(cond: Boolean): Ordered[A]

    Implicit information
      This member is added by an implicit conversion from Ordered[A] to Ensuring[Ordered[A]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring

16. #### def equals(arg0: Any): Boolean

    Definition Classes
      Any

17. #### def formatted(fmtstr: String): String

    Returns string formatted according to given `format` string.

    Returns string formatted according to given `format` string. Format strings are as for `String.format` (@see java.lang.String.format).

    Implicit information
      This member is added by an implicit conversion from Ordered[A] to StringFormat[Ordered[A]] performed by method StringFormat in scala.Predef.
    Definition Classes
      StringFormat
    Annotations
      @inline()

18. #### def hashCode(): Int

    Definition Classes
      Any

19. #### final def isInstanceOf[T0]: Boolean

    Definition Classes
      Any

20. #### def toString(): String

    Definition Classes
      Any

21. #### def →[B](y: B): (Ordered[A], B)

    Implicit information
      This member is added by an implicit conversion from Ordered[A] to ArrowAssoc[Ordered[A]] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
      ArrowAssoc

### Shadowed Implicit Value Members

1. #### def <(that: Ordered[A]): Boolean

   Returns true if `this` is less than `that`

   Returns true if `this` is less than `that`

   Implicit information
     This member is added by an implicit conversion from Ordered[A] to Ordered[Ordered[A]] performed by method orderingToOrdered in scala.math.Ordered. This conversion will take place only if an implicit value of type Ordering[Ordered[A]] is in scope.
   Shadowing
     This implicitly inherited member is shadowed by one or more members in this class.
     To access this member you can use a type ascription:

         (ordered: Ordered[Ordered[A]]).<(that)

2. #### def <=(that: Ordered[A]): Boolean

   Returns true if `this` is less than or equal to `that`.

   Returns true if `this` is less than or equal to `that`.

   Implicit information
     This member is added by an implicit conversion from Ordered[A] to Ordered[Ordered[A]] performed by method orderingToOrdered in scala.math.Ordered. This conversion will take place only if an implicit value of type Ordering[Ordered[A]] is in scope.
   Shadowing
     This implicitly inherited member is shadowed by one or more members in this class.
     To access this member you can use a type ascription:

         (ordered: Ordered[Ordered[A]]).<=(that)

3. #### def >(that: Ordered[A]): Boolean

   Returns true if `this` is greater than `that`.

   Returns true if `this` is greater than `that`.

   Implicit information
     This member is added by an implicit conversion from Ordered[A] to Ordered[Ordered[A]] performed by method orderingToOrdered in scala.math.Ordered. This conversion will take place only if an implicit value of type Ordering[Ordered[A]] is in scope.
   Shadowing
     This implicitly inherited member is shadowed by one or more members in this class.
     To access this member you can use a type ascription:

         (ordered: Ordered[Ordered[A]]).>(that)

4. #### def >=(that: Ordered[A]): Boolean

   Returns true if `this` is greater than or equal to `that`.

   Returns true if `this` is greater than or equal to `that`.

   Implicit information
     This member is added by an implicit conversion from Ordered[A] to Ordered[Ordered[A]] performed by method orderingToOrdered in scala.math.Ordered. This conversion will take place only if an implicit value of type Ordering[Ordered[A]] is in scope.
   Shadowing
     This implicitly inherited member is shadowed by one or more members in this class.
     To access this member you can use a type ascription:

         (ordered: Ordered[Ordered[A]]).>=(that)

5. #### def compare(that: Ordered[A]): Int

   Result of comparing `this` with operand `that`.

   Result of comparing `this` with operand `that`.

   Implement this method to determine how instances of A will be sorted.

   Returns `x` where:

   - `x < 0` when `this < that`
   - `x == 0` when `this == that`
   - `x > 0` when `this > that`
   Implicit information
     This member is added by an implicit conversion from Ordered[A] to Ordered[Ordered[A]] performed by method orderingToOrdered in scala.math.Ordered. This conversion will take place only if an implicit value of type Ordering[Ordered[A]] is in scope.
   Shadowing
     This implicitly inherited member is shadowed by one or more members in this class.
     To access this member you can use a type ascription:

         (ordered: Ordered[Ordered[A]]).compare(that)

6. #### def compareTo(that: Ordered[A]): Int

   Result of comparing `this` with operand `that`.

   Result of comparing `this` with operand `that`.

   Implicit information
     This member is added by an implicit conversion from Ordered[A] to Ordered[Ordered[A]] performed by method orderingToOrdered in scala.math.Ordered. This conversion will take place only if an implicit value of type Ordering[Ordered[A]] is in scope.
   Shadowing
     This implicitly inherited member is shadowed by one or more members in this class.
     To access this member you can use a type ascription:

         (ordered: Ordered[Ordered[A]]).compareTo(that)

   Definition Classes
     Ordered → Comparable

### Inherited from Comparable[A]

### Inherited from Any

### Inherited by implicit conversion orderingToOrdered from Ordered[A] to Ordered[Ordered[A]]

### Inherited by implicit conversion any2stringadd from Ordered[A] to any2stringadd[Ordered[A]]

### Inherited by implicit conversion StringFormat from Ordered[A] to StringFormat[Ordered[A]]

### Inherited by implicit conversion Ensuring from Ordered[A] to Ensuring[Ordered[A]]

### Inherited by implicit conversion ArrowAssoc from Ordered[A] to ArrowAssoc[Ordered[A]]

### Ungrouped