diff --git a/src/ch19-01-all-the-places-for-patterns.md b/src/ch19-01-all-the-places-for-patterns.md index 5200a01b5..11f5919a4 100644 --- a/src/ch19-01-all-the-places-for-patterns.md +++ b/src/ch19-01-all-the-places-for-patterns.md @@ -84,11 +84,11 @@ background color`. You can see that `if let` can also introduce new variables which shadow existing variables in the same way that `match` arms can: the line `if let Ok(age) = age` -introduces a new shadowed `age` variable that contains the value inside the `Ok` -variant. This means we need to place the `if age > 30` condition within that -block: we can’t combine these two conditions into `if let Ok(age) = age && age > -30`. The shadowed `age` we want to compare to 30 isn’t valid until the new scope -starts with the curly bracket. +introduces a new `age` variable that contains the value inside the `Ok` variant, +shadowing the existing `age` variable. This means we need to place the `if age > +30` condition within that block: we can’t combine these two conditions into `if +let Ok(age) = age && age > 30`. The new `age` we want to compare to 30 isn’t +valid until the new scope starts with the curly bracket. The downside of using `if let` expressions is that the compiler doesn’t check for exhaustiveness, whereas with `match` expressions it does. If we omitted the