虽然双引号隐式地把数据类型定义为字符串，但是以上方法显式地把concat 2函数的输入和输出类型定义为字符串。

Though the double quotes implicitly types data as strings, the above method explicitly types both the input and output to the concat2 function as strings.

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您可以通过使用Import功能并选择您先前导入到工作台的文件来定义输入和输出消息；它包含函数的输入和输出类型。

You can define input and output messages by using the import function and selecting the file you imported to the workbench earlier; it contains the input and output types for the function.

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描述类型批注的概念，以及如何在函数定义中使用它来控制输入和输出数据类型。

Describes the concept of type annotation and how to use it in a function definition to control the input and output data types.

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