if
表达式 的用法与其他语言中的 if
语句完全一样。
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此外,你还可以将 if
用作一个表达式。每个块的最后一个表达式 将成为 if
表达式的值:
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Speaker Notes
This slide should take about 4 minutes.
Because if
is an expression and must have a particular type, both of its branch blocks must have the same type. Show what happens if you add ;
after "small"
in the second example.
如果在表达式中使用 if
,则表达式中必须包含 ;
来将其与下一个语句分隔开。移除 println!
前面的 ;
即可查看编译器错误。