What is ordinal in Java enum?
What is ordinal in Java enum?
The ordinal() method returns the order of an enum instance. It represents the sequence in the enum declaration, where the initial constant is assigned an ordinal of ‘0’ . It is very much like array indexes. It is designed for use by sophisticated enum-based data structures, such as EnumSet and EnumMap .
How do you find the ordinal of an enum?
The java. lang. Enum. ordinal() method returns the ordinal of this enumeration constant (its position in its enum declaration, where the initial constant is assigned an ordinal of zero).
In which package enum is present in Java?
Class Enum> This is the common base class of all Java language enumeration types. More information about enums, including descriptions of the implicitly declared methods synthesized by the compiler, can be found in section 8.9 of The Java™ Language Specification .
What is difference between ordinal () and CompareTo () in enum?
Every enum constant is static. Hence, we can access it by using enum Name….Java.
| Ordinal() Method | CompareTo() Method |
|---|---|
| It doesn’t take any argument. | It takes an enum constant as an argument. |
What is the use of enum in Java?
What is Enum in Java. Enum in Java is a keyword, a feature which is used to represent fixed number of well-known values in Java, For example, Number of days in Week, Number of planets in Solar system etc.
When to use enum or collection in Java?
The very purpose of enum is to enforce compile time type safety. enum keyword is reserved keyword in Java. We should use enum when we know all possible values of a variable at compile time or design time , though we can add more values in future as and when we identify them.
Is Java enum the same as integers?
The Java type system, however, treats enumerations as a type separate from integers, and intermixing of enum and integer values is not allowed. In fact, an enum type in Java is actually a special compiler-generated class rather than an arithmetic type, and enum values behave as global pre-generated instances of that class.
How are enums internally represented in Java?
The EnumSet is a specialized Set implementation to be used with enum types. They are represented internally as bit vectors. The elements in an enum set must have a single enum type and Null elements are not allowed in the set. The EnumSet cannot be instantiated using a constructor; instead, there are many factory methods to do the same.