JavaScript_Succinctly

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var john = new Person(); // No argument is passed so fullName is not added to the instance. console.log(john.whatIsMyFullName()); // Logs 'John Doe'. The concept to take away here is that the keyword this is used to refer to instances when used inside of a method contained in the prototype object. If the instance does not contain the property, the prototype lookup begins. Notes If the instance or the object pointed to by this does not contain the property being referenced, the same rules that apply to any property lookup are applied, and the property will be "looked up" on the prototype chain. So in our example, if the fullName property was not contained within our instance, fullName would be looked for at Person.prototype.fullName, then Object.prototype.fullName. 112
Chapter 13 Scope and Closures Conceptual overview of <strong>JavaScript</strong> scope In <strong>JavaScript</strong>, scope is the context in which code is executed. There are three types of scope: global scope, local scope (sometimes referred to as "function scope"), and eval scope. Code defined using var inside of a function is locally scoped, and is only "visible" to other expressions in that function, which includes code inside any nested/child functions. Variables defined in the global scope can be accessed from anywhere because it is the highest level and last stop in the scope chain. Examine the code that follows and make sure you understand that each declaration of foo is unique because of scope. Sample: sample110.html var foo = 0; // Global scope. console.log(foo); // Logs 0. var myFunction = function () { var foo = 1; // Local scope. console.log(foo); // Logs 1. var myNestedFunction = function () { var foo = 2; // Local scope. console.log(foo); // Logs 2. } (); } (); eval('var foo = 3; console.log(foo);'); // eval() scope. Make sure you understand that each foo variable contains a different value because each one is defined in a specifically delineated scope. 113
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By Cody Lindley Foreword by Daniel
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Table of Contents About the Author
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Object() object instance properties
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The Story behind the Succinctly Ser
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About the Author Cody Lindley is a
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Advanced technical books written ab
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“Consider that the cody object cr
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Chapter 1 JavaScript Objects Creati
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Using JavaScript, the getGender met
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* The String() constructor function
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new object that is returned from th
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Notes The Math object is the oddbal
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In this snippet, we created a new s
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Verify that literals are created fr
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The primitive values null, undefine
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The concept to take away here is th
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* This will throw an error and not
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copied, but not the actual value. T
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Sample: sample21.html // Primitive
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Notes Careful! If you mutate the na
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console.log(instanceOfCustomObject.
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myObject.prop = 'test'; myArray.pro
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Chapter 2 Working with Objects and
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Sample: sample31.html // Encapsula
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cody['getGender']() // Just slap th
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een defined. You might think that b
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console.log(myArray.toLocaleString(
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Sample: sample44.html var cody = {
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Sometimes a web browser manufacture
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I like this library because it take
Page 62 and 63: console.log(stringObject); // Logs
Page 64 and 65: Chapter 4 Number() Conceptual overv
Page 66 and 67: NEGATIVE_INFINITY POSITIVE_INFINIT
Page 68 and 69: Parameter passed to Boolean() = Mat
Page 70 and 71: console.log(Boolean(Math)); console
Page 72 and 73: var numberObject = new Number(1.100
Page 74 and 75: Chapter 7 Null Conceptual overview
Page 76 and 77: Chapter 8 Undefined Conceptual over
Page 78 and 79: Chapter 9 The Head/Global Object Co
Page 80 and 81: object. } // Logs bar, foo's value
Page 82 and 83: Make sure you understand that the h
Page 84 and 85: Object() parameters The Object() co
Page 86 and 87: Sample: sample72.html var cody = n
Page 88 and 89: Logs 'foo', being found at Object.p
Page 90 and 91: Sample: sample77.html var addFunct
Page 92 and 93: Sample: sample79.html var yelp = f
Page 94 and 95: parameters when defining the functi
Page 96 and 97: Notes The arguments.length property
Page 98 and 99: Invoking a function (function, meth
Page 100 and 101: Self-invoking anonymous function st
Page 102 and 103: the bar variable. All this is to sh
Page 104 and 105: Chapter 12 The this Keyword Concept
Page 106 and 107: Clearly, the value of this is based
Page 108 and 109: Working around the nested function
Page 110 and 111: What you need to learn here is that
Page 114 and 115: Notes An unlimited number of functi
Page 116 and 117: } (); How is the value of sayHiTex
Page 118 and 119: var parentFunction = function () {
Page 120 and 121: Chapter 14 Function Prototype Prope
Page 122 and 123: Sample: sample119.html var myFunct
Page 124 and 125: In this example, the foo property i
Page 126 and 127: console.log(FooInstance.constructor
Page 128 and 129: Providing a new object as the proto
Page 130 and 131: var chuck = new Person(0, 0); conso
Page 132 and 133: An Array() is just a special type o
Page 134 and 135: It is more common to see an array d
Page 136 and 137: console.log(myArray.length); // Log
Page 138 and 139: while (myArrayLength--) { // If len
Page 140 and 141: ceil() cos() exp() floor() log() ma
Page 142 and 143: That is: a complex value is equal t
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JavaScript_Succinctly

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