Document destructuring defaults

evite · Aug 29, 2015 · 10aca2a · 10aca2a
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diff --git a/documentation/coffee/constructor_destructuring.coffee b/documentation/coffee/constructor_destructuring.coffee
@@ -1,6 +1,6 @@
 class Person
- constructor: (options) -> 
- {@name, @age, @height} = options
+ constructor: (options) ->
+ {@name, @age, @height = 'average'} = options
 
-tim = new Person age: 4
+tim = new Person name: 'Tim', age: 4
 
diff --git a/documentation/index.html.js b/documentation/index.html.js
@@ -766,9 +766,7 @@ Expressions
  <p>
  <span id="destructuring" class="bookmark"></span>
  <b class="header">Destructuring Assignment</b>
- To make extracting values from complex arrays and objects more convenient,
- CoffeeScript implements ECMAScript Harmony's proposed
- <a href="https://wiki.ecmascript.org/doku.php?id=harmony:destructuring">destructuring assignment</a>
+ Just like JavaScript (since ES2015), CoffeeScript has destructuring assignment
  syntax. When you assign an array or object literal to a value, CoffeeScript
  breaks up and matches both sides against each other, assigning the values
  on the right to the variables on the left. In the simplest case, it can be
@@ -797,7 +795,13 @@ Expressions
  Destructuring assignment is also useful when combined with class constructors
  to assign properties to your instance from an options object passed to the constructor.
  </p>
- <%= codeFor('constructor_destructuring', 'tim.age') %>
+ <%= codeFor('constructor_destructuring', 'tim.age + " " + tim.height') %>
+ <p>
+ The above example also demonstrates that if properties are missing in the
+ destructured object or array, you can, just like in JavaScript, provide
+ defaults. The difference with JavaScript is that CoffeeScript, as always,
+ treats both null and undefined the same.
+ </p>
 
  <p>
  <span id="fat-arrow" class="bookmark"></span>