added more literal and constructor patterns

chuanxshi · chuanxshi · commit 7bcb1acf7f43 · 2012-01-16T23:57:10.000+08:00
diff --git a/literals-and-constructors/json.html b/literals-and-constructors/json.html
@@ -0,0 +1,26 @@
+<!doctype html>
+<html lang="en">
+<head>
+<title>JavaScript Patterns</title>
+<meta charset="utf-8">
+</head>
+<body>
+<script>
+/* Title: Working with JSON
+   Description: use library from JSON.org or YUI, jQuery library
+*/
+
+// an input JSON string
+var jstr = '{"mykey": "my value"}';
+
+// antipattern
+var data = eval('(' + jstr + ')');
+
+// preferred
+// JSON.org library
+var data = JSON.parse(jstr);
+console.log(data.mykey); // "my value"
+
+</script>
+</body>
+</html>
diff --git a/literals-and-constructors/primitive-wrappers.html b/literals-and-constructors/primitive-wrappers.html
@@ -0,0 +1,50 @@
+<!doctype html>
+<html lang="en">
+<head>
+<title>JavaScript Patterns</title>
+<meta charset="utf-8">
+</head>
+<body>
+<script>
+/* Title: Primitive Wrappers
+   Description: JavaScript has 3 primitive wrapper objects: number, string, boolean
+*/
+
+// antipattern
+// with wrappers
+var s = new String("my string");
+var n = new Number(101);
+var b = new Boolean(true);
+
+// preferred
+// without wrappers
+var s = "my string";
+var n = 101;
+var b = true;
+
+/* 
+   only use primitive wrappers when you want to augment the value and persist state
+*/
+
+// primitive string
+var greet = "Hello there";
+// primitive is converted to an object
+// in order to use the split() method
+greet.split(' ')[0]; // "Hello"
+// attemting to augment a primitive is not an error
+greet.smile = true;
+// but it doesn't actually work
+console.log(typeof greet.smile); // "undefined"
+
+// primitive string
+var greet = new String("Hello there");
+// primitive is converted to an object
+// in order to use the split() method
+greet.split(' ')[0]; // "Hello"
+// attemting to augment a primitive is not an error
+greet.smile = true;
+// but it doesn't actually work
+console.log(typeof greet.smile); // "boolean"
+</script>
+</body>
+</html>
diff --git a/literals-and-constructors/regular-expression-literal.html b/literals-and-constructors/regular-expression-literal.html
@@ -0,0 +1,21 @@
+<!doctype html>
+<html lang="en">
+<head>
+<title>JavaScript Patterns</title>
+<meta charset="utf-8">
+</head>
+<body>
+<script>
+/* Title: Regular Expression Literal
+   Description: the regular expression literal notation is shorter
+*/
+
+// antipattern
+var re = new RegExp("\\\\", "gm");
+
+// preferred
+var re = /\\/gm;
+
+</script>
+</body>
+</html>
