format examples

src/content/language/variables.md

@@ -290,51 +290,59 @@ cannot be changed: they're _immutable_.
 For more information on using `const` to create constant values, see
 [Lists][], [Maps][], and [Classes][].
 
-## Wildcard variables
-
-A wildcard variable declares a local variable or parameter that is non-binding;
-essentially, a placeholder.
-You can declare a wildcard variable using the name `_`. 
-
-Because it does not bind to anything, you can have multiple declarations named
-`_` in the same namespace without a collision error.
-
-```dart
-// local variable declaration
-main() {
-  var _ = 1;
-  int _ = 2;
-}
 
-// for loop varibale declartaion
-for (var _ in list) {}
-
-// catch clause parameters
-try {
-  throw '!';
-} catch (_) {
-  print('oops');
-}
-
-// generic type and function type parameters
-class T<_> {}
-void genericFunction<_>() {}
-
-takeGenericCallback(<_>() => true);
-
-// function parameters
-Foo(_, this._, super._, void _()) {}
-
-list.where((_) => true);
-
-void f(void g(int _, bool _)) {}
+## Wildcard variables
 
-typedef T = void Function(String _, String _);
-```
+A wildcard variable with the name `_` declares a local variable or parameter
+that is non-binding; essentially, a placeholder.
+The initializer, if there is one, is still executed, but the value is not accessible.
+Multiple declarations named `_` can exist in the same namespace without a collision error.
 
-Any declarations local to a block scope is a valid use for wildcard variables.
 Top-level declarations or members where library privacy might be affected are
 not valid uses for wildcard variables.
+Declarations local to a block scope, such as the following examples,
+can declare a wildcard:
+
+* Local variable declaration.
+  ```dart
+  main() {
+    var _ = 1;
+    int _ = 2;
+  }
+  ```
+
+* For loop varibale declartaion.
+  ```dart
+  for (var _ in list) {}
+  ```
+
+* Catch clause parameters.
+  ```dart
+  try {
+    throw '!';
+  } catch (_) {
+    print('oops');
+  }
+  ```
+
+* Generic type and function type parameters.
+  ```dart
+  class T<_> {}
+  void genericFunction<_>() {}
+
+  takeGenericCallback(<_>() => true);
+  ```
+
+* Function parameters.
+  ```dart
+  Foo(_, this._, super._, void _()) {}
+
+  list.where((_) => true);
+
+  void f(void g(int _, bool _)) {}
+
+  typedef T = void Function(String _, String _);
+  ```
 
 
 [Assert]: /language/error-handling#assert