Coding All-in-One For Dummies

The go-to guide for learning coding from the ground-up

Adding some coding know-how to your skills can help launch a new career or bolster an old one. Coding All-in-One For Dummies offers an ideal starting place for learning the languages that make technology go. This edition gets you started with a helpful explanation of how coding works and how it’s applied in the real-world before setting you on a path toward writing code for web building, mobile application development, and data analysis. Add coding to your skillset for your existing career, or begin the exciting transition into life as a professional developer—Dummies makes it easy.

• Learn coding basics and how to apply them
• Analyze data and automate routine tasks on the job
• Get the foundation you need to launch a career as a coder
• Add HTML, JavaScript, and Python know-how to your resume

This book serves up insight on the basics of coding, designed to be easy to follow, even if you’ve never written a line of code in your life. You can do this.

This All-in-One includes work by expert coders and coding educators, including Chris Minnick and Eva Holland coauthors of Coding with JavaScript For Dummies; Nikhil Abraham, author of Coding For Dummies and Getting a Coding Job For Dummies; John Paul Mueller and Luca Massaron, coauthors of Python for Data Science For Dummies and Machine Learning For Dummies; and Barry Burd, author of Flutter For Dummies.

Introduction 1

About This Book 2

Foolish Assumptions 2

Icons Used in This Book 3

Beyond the Book 4

Where to Go from Here 4

Book 1: Getting Started with Coding 5

Chapter 1: What Is Coding? 7

Defining What Code Is 8

Following instructions 8

Writing code with some Angry Birds 9

Understanding What Coding Can Do for You 10

Eating the world with software 10

Coding on the job 12

Scratching your own itch (and becoming rich and famous) 13

Surveying the Types of Programming Languages 13

Comparing low-level and high-level programming languages 14

Contrasting compiled code and interpreted code 15

Programming for the web 16

Taking a Tour of a Web App Built with Code 16

Defining the app’s purpose and scope 16

Standing on the shoulders of giants 17

Chapter 2: Programming for the Web 19

Displaying Web Pages on Your Desktop and Mobile Device 20

Hacking your favorite news website 20

Understanding how the World Wide Web works 23

Watching out for your frontend and backend 24

Defining web and mobile applications 25

Coding Web Applications 26

Starting with HTML, CSS, and JavaScript 26

Adding logic with Python, Ruby, or PHP 27

Coding Mobile Applications 28

Building mobile web apps 29

Building native mobile apps 30

Deploying Web Applications in the Cloud 31

Chapter 3: Becoming a Programmer 33

Writing Code Using a Process 34

Researching what you want to build 35

Designing your app 36

Coding your app 37

Debugging your code 38

Picking Tools for the Job 39

Working offline 39

Working online with CodeSandbox.io 40

Book 2: Basic Web Coding 43

Chapter 1: Exploring Basic HTML 45

What Does HTML Do? 46

Understanding HTML Structure 47

Identifying elements 47

Featuring your best attribute 49

Standing head, title, and body above the rest 50

Getting Familiar with Common HTML Tasks and Elements 52

Writing headlines 53

Organizing text in paragraphs 54

Linking to your (heart’s) content 55

Adding images 56

Styling Me Pretty 58

Highlighting with bold, italics, underline, and strikethrough 58

Raising and lowering text with superscript and subscript 59

Building Your First Website Using HTML 60

Chapter 2: Getting More Out of HTML 63

Organizing Content on the Page 64

Listing Data 66

Creating ordered and unordered lists 66

Nesting lists 67

Putting Data in Tables 68

Basic table structuring 69

Stretching table columns and rows 70

Aligning tables and cells 72

Filling Out Forms 75

Understanding how forms work 75

Creating basic forms 76

Practicing More with HTML 78

Chapter 3: Getting Stylish with CSS 79

What Does CSS Do? 79

CSS Structure 81

Choosing the element to style 81

My property has value 83

Hacking the CSS on your favorite website 84

Common CSS Tasks and Selectors 86

Font gymnastics: Size, color, style, family, and decoration 86

Customizing links 90

Adding background images and styling foreground images 93

Getting Stylish 97

Adding CSS to your HTML 97

Practicing with CSS 99

Chapter 4: Next Steps with CSS 101

Styling (More) Elements on Your Page 102

Styling lists 102

Designing tables 105

Selecting Elements to Style 107

Styling specific elements 107

Naming HTML elements 112

Aligning and Laying Out Your Elements 113

Organizing data on the page 114

Shaping the div 116

Understanding the box model 117

Positioning the boxes 119

Writing More Advanced CSS 122

Chapter 5: Responsive Layouts with Flexbox 123

Introducing Responsive Design 124

The web is mobile 124

Why are so many sites mobile-unfriendly? 124

Introducing mobile-first design 124

Making responsive web pages with the viewport meta tag 125

Using Flexbox 128

Creating boxes 129

Thinking in one dimension 130

Using multi-line containers 133

Make no assumptions 134

Aligning on the cross-axis 134

Aligning on the main axis 136

Modifying flexible boxes 137

Changing the order of items 139

Experimenting with Flexbox 140

Chapter 6: Styling with Bootstrap 143

Figuring Out What Bootstrap Does 144

Installing Bootstrap 145

Understanding the Layout Options 147

Lining up on the grid system 147

Dragging and dropping to a website 150

Using predefined templates 151

Adapting layout for mobile, tablet, and desktop 151

Coding Basic Web Page Elements 153

Designing buttons 153

Navigating with toolbars 155

Adding icons 157

Practicing with Bootstrap 158

Book 3: Advanced Web Coding 159

Chapter 1: What Is JavaScript? 161

What Is JavaScript? 161

The Eich-man cometh 162

Mocha-licious 163

We need more effects! 163

JavaScript Grows Up 164

Dynamic scripting language 165

What does JavaScript do? 166

Why JavaScript? 167

JavaScript is easy to learn! 168

JavaScript is everywhere! 169

JavaScript is powerful! 172

JavaScript is in demand! 172

Chapter 2: Writing Your First JavaScript Program 173

Setting Up Your Development Environment 173

Downloading and installing Chrome 174

Downloading and installing a code editor 174

Reading JavaScript Code 181

Running JavaScript in the Browser Window 182

Using JavaScript in an HTML event attribute 182

Using JavaScript in a script element 183

Including external JavaScript files 185

Using the JavaScript Developer Console 188

Commenting Your Code 189

Single-line comments 190

Multi-line comments 190

Using comments to prevent code execution 191

Chapter 3: Working with Variables 193

Understanding Variables 193

Initializing Variables 195

Understanding Global and Local Scope 197

Naming Variables 199

Creating Constants Using the const Keyword 201

Working with Data Types 202

Number data type 202

bigInt data type 205

String data type 205

Boolean data type 208

NaN data type 209

Undefined data type 210

Symbol data type 210

Chapter 4: Understanding Arrays 211

Making a List 211

Array Fundamentals 213

Arrays are zero-indexed 213

Arrays can store any type of data 214

Creating Arrays 215

Using the new keyword method 215

Array literal 215

Populating Arrays 215

Understanding Multidimensional Arrays 216

Accessing Array Elements 218

Looping through arrays 219

Array properties 220

Array methods 220

Using array methods 222

Chapter 5: Working with Operators, Expressions, and Statements 225

Express Yourself 226

Hello, Operator 226

Operator precedence 226

Using parentheses 227

Types of Operators 230

Assignment operators 230

Comparison operators 231

Arithmetic operators 231

String operator 234

Bitwise operators 234

Logical operators 236

Special operators 237

Combining operators 239

Chapter 6: Getting into the Flow with Loops and Branches 241

Branching Out 241

if else statements 242

Switch statements 243

Here We Go: Loop De Loop 246

for loops 246

for in loops 248

while loops 251

do while loops 252

break and continue statements 253

Chapter 7: Getting Functional 255

Understanding the Function of Functions 255

Using Function Terminology 257

Defining a function 257

Function head 257

Function body 257

Calling a function 258

Defining parameters and passing arguments 258

Returning a value 258

The Benefits of Using Functions 258

Writing Functions 262

Returning Values 263

Passing and Using Arguments 264

Passing arguments by value 265

Passing arguments by reference 267

Calling a function without all the arguments 267

Setting default parameter values 267

Calling a function with more arguments than parameters 268

Getting into arguments with the arguments object 268

Understanding Function Scope 269

Creating Anonymous Functions 270

Knowing the differences between anonymous and named functions 270

Arrow functions 270

Doing it Again with Recursion 271

Functions within Functions 273

Chapter 8: Making and Using Objects 275

Object of My Desire 275

Creating Objects 277

Defining objects with object literals 277

Defining objects with a constructor function 278

Making objects with class 279

Using Object.create 280

Retrieving and Setting Object Properties 280

Using dot notation 281

Using square bracket notation 281

Deleting Properties 283

Working with Methods 284

Using this 286

An Object-Oriented Way to Become Wealthy: Inheritance 287

Creating an object using inheritance 288

Modifying an object type 289

Chapter 9: Controlling the Browser with the Window Object 291

Understanding the Browser Environment 291

The user interface 292

Loader 293

HTML parsing 294

CSS parsing 294

JavaScript parsing 294

Layout and rendering 295

Investigating the BOM 295

The Navigator object 295

The Window object 298

Using the Window object’s methods 304

Chapter 10: Manipulating Documents with the DOM 307

Understanding the DOM 307

Understanding Node Relationships 309

Using the Document Object’s Properties and Methods 314

Using the Element Object’s Properties and Methods 316

Working with the Contents of Elements 319

innerHTML 319

Setting attributes 320

Getting Elements by ID, Tag Name, or Class 320

getElementById 321

getElementsByTagName 322

getElementsByClassName 322

Using the Attribute Object’s Properties 324

Creating and Appending Elements 325

Removing Elements 325

Chapter 11: Using Events in JavaScript 327

Knowing Your Events 327

Handling Events 329

Using inline event handlers 330

Event handling using element properties 331

Event handling using addEventListener 332

Stopping propagation 336

Chapter 12: Integrating Input and Output 339

Understanding HTML Forms 339

The form element 340

The label element 341

The input element 342

The select element 344

The textarea element 344

The button element 344

Working with the Form Object 345

Using Form properties 345

Using the Form object’s methods 347

Accessing form elements 348

Getting and setting form element values 349

Validating user input 351

Chapter 13: Understanding Callbacks and Closures 355

What Are Callbacks? 355

Passing functions as arguments 356

Writing functions with callbacks 356

Using named callback functions 357

Understanding Closures 360

Using Closures 363

Chapter 14: Embracing AJAX and JSON 367

Working behind the Scenes with AJAX 367

AJAX examples 368

Viewing AJAX in action 370

Using the XMLHttpRequest object 373

Working with the same-origin policy 375

Using CORS, the silver bullet for AJAX requests 377

Putting Objects in Motion with JSON 378

Book 4: Creating Mobile Apps 383

Chapter 1: What Is Flutter? 385

All About Hardware and Software 385

Where Does Flutter Fit In? 389

Cross-platform development 390

A quick-and-easy development cycle 394

A great way to think about app development 396

Enough New Terminology! What’s Next? 400

Chapter 2: Setting Up Your Computer for Mobile App Development 401

The Stuff You Need 401

What to Do 403

Getting and installing the stuff 403

For Mac users only 406

Configuring Android Studio 407

Running your first app 408

Dealing with the Devil’s Details 413

On installing Android Studio 414

On launching Android Studio for the first time 414

On adding virtual devices 415

On installing Flutter 416

Divisiveness Among Devices 418

Running apps on an Android device 418

Testing apps on a physical device 419

Using Android Studio 424

Starting up 425

The main window 425

Running This Book’s Sample Programs 429

Enjoying reruns 431

If you’re finicky 432

Chapter 3: “Hello” from Flutter 433

First Things First: Creating a Flutter Project 434

What’s it all about? 436

A constructor’s parameters 440

A note about punctuation 442

Don’t relent — simply indent 442

Classes, Objects, and Widgets 444

A brief treatise on “within-ness” 446

The documentation is your friend 447

Making Things Look Nicer 448

Creating a scaffold 451

Adding visual tweaks 453

Dart’s enum feature 454

Hello from sunny California! 454

Adding another widget 456

Centering the text (Part 1) 459

Centering the text (Part 2) 461

Displaying an image 464

Hey, Wait a Minute 468

Chapter 4: Hello Again 469

Creating and Using a Function 470

The function declaration 471

A function call 472

Parameters and the return value 472

Programming in Dart: The Small Stuff 475

Statements and declarations 475

Dart’s typing feature 476

Literals, variables, and expressions 477

Two for the price of one 480

Dart’s var keyword 483

Built-in types 484

Types that aren’t built-in 486

Using import declarations 487

Creating Function Declaration Variations 487

Type names in function declarations 490

Naming your parameters 491

What about the build function? 492

More Fun to Come! 493

Chapter 5: Making Things Happen 495

Let’s All Press a Floating Action Button 495

Stateless widgets and stateful widgets 498

Widgets have methods 498

Pay no attention to the framework behind the curtain 500

Enhancing Your App 509

More parameters, please 512

The override annotation 514

What does <Widget> mean? 515

Anonymous functions 516

What belongs where 519

Names that start with an underscore 524

Whew! 525

Chapter 6: Laying Things Out 527

Understanding the Big Picture 528

Creating bite-size pieces of code 531

Creating a parameter list 533

Living color 534

Adding padding 535

Your humble servant, the Column widget 537

The SizedBox widget 539

Your friend, the Container widget 539

Nesting Rows and Columns 545

Introducing More Levels of Nesting 546

Using the Expanded Widget 549

Expanded versus unexpanded 552

Expanded widget saves the day 555

Flexing some muscles 560

How Big Is My Device? 562

Chapter 7: Interacting with the User 567

A Simple Switch 568

Dart’s const keyword 571

Compatible or NOT? 572

Wait For It! 574

How Much Do You Love Flutter? 576

Dealing with Text Fields 581

Callouts 1 and 2 582

Callout 3 585

Callout 4 586

Callout 5 590

Creating Radio Buttons 590

Creating an enum 593

Building the radio group 593

Displaying the user’s choice 595

Creating a Drop-Down Button 596

Building the drop-down button 600

The little Reset button 601

Making a map 602

Onward and Upward 603

Chapter 8: Navigation, Lists, and Other Goodies 605

Extending a Dart Class 605

Navigating from One Page to Another 608

An icon on a button 612

Pushing and popping 612

Passing Data from the Source to a Destination 613

Passing Data Back to the Source 618

Dart’s async and await keywords 621

Taking control of the app bar’s Back button 623

Passing Data in Both Directions 624

Creating Named Routes 629

Creating a List 633

The ListView widget 634

Creating list items one-by-one 639

Making loops with Dart 643

Fetching Data from the Internet 646

Using a public API 647

Sending an URL to a server 650

Making sense of a JSON response 651

What’s Next? 652

Chapter 9: Moving Right Along 653

Setting the Stage for Flutter Animation 653

Moving Along a Straight Line 659

Bouncing Around 664

Animating Size and Color Changes 666

Moving Along a Curve 668

Dragging Things Around 670

Tearing Things Up 673

Book 5: Getting Started with Python 675

Chapter 1: Wrapping Your Head around Python 677

What Does Python Do? 678

Defining Python Structure 679

Understanding the Zen of Python 679

Styling and spacing 680

Coding Common Python Tasks and Commands 681

Defining data types and variables 681

Computing simple and advanced math 682

Using strings and special characters 684

Deciding with conditionals: if, elif, else 685

Input and output 686

Shaping Your Strings 687

Dot notation with upper(), lower(), capitalize(), and strip() 687

String formatting with % 688

Chapter 2: Installing a Python Distribution 689

Using Anaconda 690

Getting Anaconda 690

Defining why Anaconda is used in this book 691

Installing Anaconda on Linux 692

Installing Anaconda on macOS X 693

Installing Anaconda on Windows 694

Downloading the Data Sets and Example Code 696

Starting Anaconda Navigator 697

Using Jupyter Notebook 697

Defining the code repository 699

Understanding the data sets used in this book 704

Chapter 3: Working with Real Data 707

Uploading, Streaming, and Sampling Data 708

Uploading small amounts of data into memory 709

Streaming large amounts of data into memory 710

Generating variations on image data 711

Sampling data in different ways 712

Accessing Data in Structured Flat-File Form 714

Reading from a text file 714

Reading CSV-delimited format 715

Reading Excel and other Microsoft Office files 718

Sending Data in Unstructured File Form 719

Managing Data from Relational Databases 722

Interacting with Data from NoSQL Databases 724

Accessing Data from the Web 725

Accessing XML data 725

Using read_xml 727

Book 6: Data Analysis with Python 729

Chapter 1: Conditioning Your Data 731

Juggling between NumPy and pandas 732

Knowing when to use NumPy 732

Knowing when to use pandas 732

Validating Your Data 733

Figuring out what’s in your data 734

Removing duplicates 737

Creating a data map and data plan 738

Manipulating Categorical Variables 740

Creating categorical variables 741

Renaming levels 742

Combining levels 743

Dealing with Dates in Your Data 744

Formatting date and time values 745

Using the right time transformation 745

Dealing with Missing Data 747

Finding the missing data 747

Encoding missingness 748

Imputing missing data 749

Slicing and Dicing: Filtering and Selecting Data 750

Slicing rows 750

Slicing columns 751

Dicing 752

Concatenating and Transforming 752

Adding new cases and variables 753

Removing data 754

Sorting and shuffling 755

Aggregating Data at Any Level 757

Chapter 2: Shaping Data 759

Working with HTML Pages 760

Parsing XML and HTML 760

Using XPath for data extraction 761

Working with Raw Text 763

Dealing with Unicode 763

Stemming and removing stop words 764

Introducing regular expressions 766

Using the Bag of Words Model and Beyond 768

Understanding the bag of words model 769

Working with n-grams 771

Implementing TF-IDF transformations 772

Working with Graph Data 774

Understanding the adjacency matrix 775

Using NetworkX basics 775

Chapter 3: Getting a Crash Course in MatPlotLib 779

Starting with a Graph 780

Defining the plot 780

Drawing multiple lines and plots 781

Saving your work 782

Setting the Axis, Ticks, Grids 783

Getting the axes 783

Formatting the axes 784

Adding grids 785

Defining the Line Appearance 786

Working with line styles 786

Using colors 787

Adding markers 789

Using Labels, Annotations, and Legends 790

Adding labels 791

Annotating the chart 792

Creating a legend 793

Chapter 4: Visualizing the Data 795

Choosing the Right Graph 796

Showing parts of a whole with pie charts 796

Creating comparisons with bar charts 797

Showing distributions using histograms 799

Depicting groups using box plots 800

Seeing data patterns using scatterplots 802

Creating Advanced Scatterplots 803

Depicting groups 803

Showing correlations 804

Plotting Time Series 806

Representing time on axes 806

Plotting trends over time 807

Visualizing Graphs 809

Developing undirected graphs 809

Developing directed graphs 811

Book 7: Career Building with Coding 813

Chapter 1: Exploring Coding Career Paths 815

Augmenting Your Existing Job 816

Creative design 816

Content and editorial 817

Human resources 818

Product management 819

Sales and marketing 820

Legal 821

Finding a New Coding Job 822

Frontend web development 823

Backend web development 824

Mobile application development 826

Data analysis 827

Chapter 2: Exploring Undergraduate and Graduate Degrees 829

Getting a College Degree 830

College computer science curriculum 831

Doing extracurricular activities 833

Two-year versus four-year school 834

Enrolling in an Advanced Degree Program 836

Graduate school computer science curriculum 837

Performing research 838

Interning to Build Credibility 839

Types of internship programs 839

Securing an internship 840

Chapter 3: Training on the Job 843

Taking a Work Project to the Next Level 844

Learning on the Job and After Work 845

Training on the job 846

Learning after work 846

Freelancing to Build Confidence and Skills 848

Transitioning to a New Role 849

Assessing your current role 850

Networking with developers 850

Identifying roles that match your interest and skills 851

Chapter 4: Coding Career Myths 853

You Must Be Good at Math 853

You Must Have Studied Engineering 854

You Can Learn Coding in a Few Weeks 855

You Need a Great Idea to Start Coding 855

Ruby Is Better than Python 856

Only College Graduates Receive Coding Offers 856

You Must Have Experience 857

Tech Companies Don’t Hire Women or Minorities 858

The Highest Paying Coding Jobs Are in San Francisco 859

Your Previous Experience Isn’t Relevant 860

Index 861

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