when also can be used as an expression. Whatever the selected branch evaluates to is what the when returns.

The when will also have to be "exhaustive", having branches that cover every possible scenario. Usually, that means that we need an else branch.

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break Statements Capturing Values in when continue Statements else if if if as an Expression if as an Expression, Using Blocks if Without else Single-Line if when when as an Expression when with Commas when with Expressions for Branches when with Ranges when Without an Expression when Works with Any Type while
Capturing Values in when enum and when() when when as an Expression when with Commas when with Expressions for Branches when with Ranges when Without an Expression when Works with Any Type
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