Scope/Function names and labels: Difference between revisions

=={{header|Wren}}==

Firstly, Wren doesn't support labels at all.

Secondly, functions (as opposed to methods) are first-class objects and have the same visibility as any other object. In other words, when defined in a particular scope, they are visible from the point of declaration to the end of that scope.

On the other hand, methods are always public members of a class and are visible throughout that class. Although technically a top-level class is visible throughout the module in which its defined, it is null prior to its definition.

The following example illustrates these points.

<lang ecmascript>//func.call() /* invalid, can't call func before its declared */

var func = Fn.new { System.print("func has been called.") }

func.call() // fine

//C.init() /* not OK, as C is null at this point */

class C {

static init() { method() } // fine even though 'method' not yet declared

static method() { System.print("method has been called.") }

}

C.init() // fine</lang>

{{out}}

<pre>

(as it stands)

func has been called.

method has been called.

(with line 1 uncommented)

[./scope_function_names line 3] Error at '}': Variable 'func' referenced before this definition (first use at line 1).

(with only line 7 uncommented)

func has been called.

Null does not implement 'init()'.

[./scope_function_names line 7] in (script)

</pre>