C# Language Specification - Willy .Net

Chapter 14 Expressionsenclosing block (§15.2) or switch-block (§15.7.2) must refer to the same entity. [Note: This rule ensures thatthe meaning of a name is always the same within a block. end note][Example: The exampleclass Test{double x;void F(bool b) {x = 1.0;if (b) {int x = 1;}}}results in a compile-time error because x refers to different entities within the outer block (the extent ofwhich includes the nested block in the if statement). In contrast, the exampleclass Test{double x;}void F(bool b) {if (b) {x = 1.0;}else {int x = 1;}}is permitted because the name x is never used in the outer block. end example][Note: The rule of invariant meaning applies only to simple names. It is perfectly valid for the sameidentifier to have one meaning as a simple name and another meaning as right operand of a member access(§14.5.4). end note] [Example: For example:struct Point{int x, y;public Point(int x, int y) {this.x = x;this.y = y;}}The example above illustrates a common pattern of using the names of fields as parameter names in aninstance constructor. In the example, the simple names x and y refer to the parameters, but that does notprevent the member access expressions this.x and this.y from accessing the fields. end example]14.5.3 Parenthesized expressionsA parenthesized-expression consists of an expression enclosed in parentheses.parenthesized-expression:( expression )A parenthesized-expression is evaluated by evaluating the expression within the parentheses. If theexpression within the parentheses denotes a namespace, type, or method group, a compile-time error occurs.Otherwise, the result of the parenthesized-expression is the result of the evaluation of the containedexpression.139