JavaScript Cookbook, 2nd Edition

دوره آموزش Javascript

1. The JavaScript Not-So-Simple Building Blocks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Differentiating Between a JavaScript Object, Primitive, and Literal 3
1.2. Extracting a List from a String 7
1.3. Checking for an Existing, Nonempty String 10
1.4. Inserting Special Characters 14
1.5. Replacing Patterns with New Strings 16
1.6. Finding and Highlighting All Instances of a Pattern 18
1.7. Swapping Words in a String Using Capturing Parentheses 22
1.8. Replacing HTML Tags with Named Entities 25
1.9. Converting an ISO 8601 Formatted Date to a Date Object Acceptable
Format 25
1.10. Using Function Closures with Timers 29
1.11. Tracking Elapsed Time 31
1.12. Converting a Decimal to a Hexadecimal Value 32
1.13. Summing All Numbers in a Table Column 33
1.14. Converting Between Degrees and Radians 36
1.15. Find the Radius and Center of a Circle to Fit Within a Page Element 37
1.16. Calculating the Length of a Circular Arc 39
1.17. Using ES6 String Extras Without Leaving Users in the Dirt 40
2. JavaScript Arrays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
2.1. Searching Through an Array 43
2.2. Flattening a Two-Dimensional Array with concat() and apply() 45
2.3. Removing or Replacing Array Elements 46
2.4. Extracting a Portion of an Array 48

2.5. Applying a Function Against Each Array Element 48
2.6. Traversing the Results from querySelectorAll() with forEach() and call() 50
2.7. Applying a Function to Every Element in an Array and Returning a New
Array 51
2.8. Creating a Filtered Array 52
2.9. Validating Array Contents 52
2.10. Using an Associative Array to Store Form Element Names and Values 54
2.11. Using a Destructuring Assignment to Simplify Code 58
3. Functions: The JavaScript Building Blocks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
3.1. Placing Your Function and Hoisting 61
3.2. Passing a Function As an Argument to Another Function 63
3.3. Implementing a Recursive Algorithm 65
3.4. Preventing Code Blocking with a Timer and a Callback 68
3.5. Creating a Function That Remembers Its State 72
3.6. Converting Function Arguments into an Array 75
3.7. Reducing Redundancy by Using a Partial Application 77
3.8. Improving Application Performance with Memoization (Caching
Calculations) 80
3.9. Using an Anonymous Function to Wrap Global Variables 82
3.10. Providing a Default Parameter 83
4. The Malleable JavaScript Object. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
4.1. Keeping Object Members Private 86
4.2. Using Prototype to Create Objects 87
4.3. Inheriting an Object’s Functionality 90
4.4. Extending an Object by Defining a New Property 92
4.5. Preventing Object Extensibility 94
4.6. Preventing Any Changes to an Object 95
4.7. Namespacing Your JavaScript Objects 97
4.8. Rediscovering this with Prototype.bind 100
4.9. Chaining Your Object’s Methods 103
5. JavaScript and Directly Accessing the User Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
5.1. Accessing a Given Element and Finding Its Parent and Child Elements 107
5.2. Accessing All Images in the Web Page 110
5.3. Discovering All Images in Articles Using the Selectors API 116
5.4. Setting an Element’s Style Attribute 119
5.5. Applying a Striped Theme to an Unordered List 122
5.6. Finding All Elements That Share an Attribute 123
5.7. Inserting a New Paragraph 124
5.8. Adding Text to a New Paragraph 125