Summary
-
The
main
we’ve seen so far is one example of a function. -
We can define multiple other functions.
-
We can call functions similar to how we call macros (for example,
println!
). -
Functions may take parameters, which are passed in from the caller.
-
Function parameters can be used as variables inside the body of a function.
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Functions may return results of different types.
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By default, functions return the unit
()
type. -
A function body is a block, and may end with an expression, which will be its result value.
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Function parameters are scoped to the function body.
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Blocks create scopes for variables defined inside of them.
-
main
is a normal function, but has some special rules:-
It cannot take any parameters.
-
It can only have some special result types.
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