Enumerations are treated as data types, and you can use them to create sets of constants for use with variables and properties.

列举型别可视为是资料型别，您可以用来建立多组常数以便与变数和属性搭配使用。

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Type annotation of variables, constants, and functions helps reduce programming errors by limiting data appropriate types.

变数、常数和函式的型别附注借由限制资料适当型别的方式，来减少程序设计上的错误。

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