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| 2. 40. 1. 计数原理 |
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An enumeration is created using the new enum keyword. |
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enum Week {
Monday, Tuesday, Wednesday, Thursday, Friday, Saturaday, Sunday
}
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- The identifiers Monday, Tuesday, and so on, are called enumeration constants.
- Each is implicitly declared as a public, static member of Week.
- Their type is the type of the enumeration in which they are declared.
- These constants are called self-typed.
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You declare and use an enumeration variable in much the same way as the primitive types. |
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Because aWeekDay is of type Week, the only values that it can be assigned (or contain) are
those defined by the enumeration. |
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enum Week {
Monday, Tuesday, Wednesday, Thursday, Friday, Saturaday, Sunday
}
public class MainClass {
public static void main(String args[]) {
Week aWeekDay;
aWeekDay = Week.Monday;
// Output an enum value.
System.out.println("Value of aWeekDay: " + aWeekDay);
System.out.println();
}
}
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Value of aWeekDay: Monday |
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