1
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Phew.

2
00:00:09,585 --> 00:00:10,650
You've now seen

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00:00:10,650 --> 00:00:13,245
some of the subtleties of passing parameters,

4
00:00:13,245 --> 00:00:16,155
accessing global variables, don't do it,

5
00:00:16,155 --> 00:00:18,180
functions calling other functions,

6
00:00:18,180 --> 00:00:20,565
and functions having side effects.

7
00:00:20,565 --> 00:00:22,455
You should now be able to,

8
00:00:22,455 --> 00:00:25,320
avoid the use of global variables and function definitions

9
00:00:25,320 --> 00:00:28,800
by creating formal parameters for all values that are needed,

10
00:00:28,800 --> 00:00:32,910
and you should be able to identify whether a function has any side effects,

11
00:00:32,910 --> 00:00:35,355
including mutations to lists and dictionaries.

12
00:00:35,355 --> 00:00:38,730
As much as possible, I encourage you to avoid side effects,

13
00:00:38,730 --> 00:00:41,970
come as close to strict functional programming as you can.

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00:00:41,970 --> 00:00:44,370
Speaking of functional programming,

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why did the functional program returned her TV?

16
00:00:47,815 --> 00:00:50,850
Because she kept muting the sound by accident,

17
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she returned the TV and asked for one that was immutable.

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00:00:54,935 --> 00:00:59,310
Okay. That one was a stretch. We'll see you next time.