Add Episode 10 (last)

Fix typo in episode 9

CHANGELOG.md

@@ -8,12 +8,24 @@ preview_image: changelog_preview.jpg
 
 [reactive.how](http://reactive.how), learn reactive programming.
 
+## `16.0` Nov 20, 2017
+
+### 🃏
+- Add [Episode 10 - Last value?](/last)
+
+## `15.0` Nov 13, 2017
+
+### 🃏
+- Add [Episode 9 - Take 3 and complete](/take)
+
 ## `14.0` Nov 6, 2017
 
+### 🃏
 - Add [Episode 8 - zip vs combineLatest](/zip)
 
 ## `13.0` Oct 30, 2017
 
+### 🃏
 - Add [Episode 7 - combineLatest vs merge](/combineLatest)
 
 ## `12.1` Oct 24, 2017

_data/course.yml

@@ -60,3 +60,10 @@ lessons:
       - 242296640
     date: Monday, 13 Nov.
 
+  - name: Last value?
+    card: last
+    videos:
+      -
+      - 242933193
+    date: Monday, 20 Nov.
+

last.md

@@ -0,0 +1,34 @@
+---
+id: last
+lesson: 10
+title: Learn Reactive Programming - Episode 10 (Last)
+layout: default
+class: post
+preview_image: last/content_preview.jpg
+preview_image_alt: The "last" operator
+---
+
+Today, we explore a card named `❚ last`. It returns the last value of a stream. As soon as the last value is emitted, it returns it? Naaah! How could one be certain that no value comes after? Reactive programming can't see the future.
+
+We have to wait for a `◉ complete` notification (read [Episode 9 - Take 3 and complete](/take) to learn more about it). Only when the stream has completed, we know this value was the last one – **and this completion may never happen**!
+
+Last Monday, we used the card `❚ take` (watch it again below). The stream it outputs has a `◉ complete` notification overlapped by the `3` value, as it completes immediately. I would like to emphasize that this notification is **not** intended to deliver the last value of the stream. It is a separate event, without a value (though it can happen immediately after an event value).
+
+To illustrate all those principles, let's see how `❚ last` and `❚ take` work with an input stream that completes **few seconds** after the last emitted value:
+
+{% include card_player.html video=242933193 episode=true %}
+
+This is how `❚ last` operates with one input stream:
+
+- **When the input stream completes**, the output stream:
+  - emits the last value emitted by the input stream
+  - and immediately completes
+
+So, this card returns a new stream of **at most** one value.
+
+## Summary
+
+- A stream can complete emitting a notification (read [Episode 9](/take))
+- The `◉ complete` notification is a special event with no value
+- A listener can subscribe to a stream and act upon its completion
+- Also, the behavior of some cards like `❚ last` is based on this notification

take.md

@@ -14,7 +14,7 @@ Here is `❚ take`, a new card from the filtering category:
 
 {% include card_player.html video=242296640 episode=true %}
 
-Use a `▬ number` on this card, such as `3`, to set a maximum _amount_ of events to emit. `❚ take` returns a new stream of **at most** _amount_ events:
+Use a `▬ number` on this card, such as `3`, to set a maximum _amount_ of events to emit. `❚ take` returns a new stream of **at most** _amount_ values:
 
 - When the input stream emits its _n-th_ value:
   - if _n_ < _amount_, the event can pass