Day 14 completed

yanpearson · yanpearson · commit 83be71702523 · 2017-02-19T17:36:12.000-05:00
diff --git a/14 - JavaScript References VS Copying/index.html b/14 - JavaScript References VS Copying/index.html
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+<!DOCTYPE html>
+<html lang="en">
+<head>
+ <meta charset="UTF-8">
+ <title>JS Reference VS Copy</title>
+</head>
+<body>
+
+ <script>
+ // start with strings, numbers and booleans
+
+ // Let's say we have an array
+ const players = ['Wes', 'Sarah', 'Ryan', 'Poppy'];
+
+ // and we want to make a copy of it.
+	const team = players;
+
+ // You might think we can just do something like this:
+ team[3] = 'Lux';
+
+ // however what happens when we update that array?
+ 
+ // now here is the problem!
+
+ // oh no - we have edited the original array too!
+
+ // Why? It's because that is an array reference, not an array copy. They both point to the same array!
+
+ // So, how do we fix this? We take a copy instead!
+ const team2 = players.slice();
+
+ // one day
+
+ // or create a new array and concat the old one in
+ const team3 = [].concat(players);
+
+ // or use the new ES6 Spread
+ const team4 = [...players];
+
+ // now when we update it, the original one isn't changed
+
+ // The same thing goes for objects, let's say we have a person object
+
+ // with Objects
+ const person ={
+ name: 'Wes Bos',
+	 age: 80
+	};
+
+ // and think we make a copy:
+ const captain = person;
+
+ // how do we take a copy instead?
+ const cap2 = Object.assign({}, person,{number: 99, age: 12 });
+
+ // We will hopefully soon see the object ...spread
+ // const cap3 ={...person};
+
+ // Things to note - this is only 1 level deep - both for Arrays and Objects. lodash has a cloneDeep method, but you should think twice before using it.
+ const wes ={
+	 name: 'Wes',
+	 age: 100,
+	 social:{
+	 twitter: '@wesbos',
+		facebook: 'wesbos.developer'
+	 }
+	};
+
+ const dev = Object.assign([], wes);
+ </script>
+
+</body>
+</html>
