1 001 TypeScript's Relationship with JavaScript Demo 04:25 2 002 JavaScript vs. TypeScript in the Build Process 02:55 3 003 Essential Tools for TypeScript Development 01:43 4 004 Set up Node.js and VS Code 01:33 5 005 Installing pnpm for Package Management 03:01 6 01:19 7 007 Unexpected Token Error in the Browser 00:48 8 008 Browsers Can't Understand TypeScript Syntax 01:20 9 009 Convert a TypeScript File into a JavaScript File 01:06 10 010 Compile TypeScript to JavaScript with the TypeScript CLI 04:05 11 011 Automating TypeScript Compilation 00:48 12 012 Use tsc's Watch Mode to Automatically Compile TypeScript Files 01:24 13 013 Compiling TypeScript Files to a Directory 01:09 14 014 Configure the Output Directory for Compiled Files 01:11 15 015 Use Vite for a Frontend App with TypeScript 01:47 16 016 Configure Vite for a Vanilla TypeScript Project 02:56 17 017 Comparing Vite with tsc 01:03 18 018 TypeScript as a Linter 03:33 19 019 TypeScript in a CI-CD System 03:41 20 020 Should TypeScript Block Your Dev Server_ 04:47 21 021 Quickly Create Scripts with tsx 01:44 22 022 Understanding Function Errors 00:51 23 01:05 24 024 Annotating Empty Parameters 00:37 25 025 Annotating Function Parameters 01:15 26 026 Basic Types in TypeScript 00:56 27 027 TypeScript Basic Types 01:37 28 028 Optional Function Parameters 00:51 29 029 Optional Function Parameters in TypeScript 00:57 30 030 Default Parameters in JavaScript Functions 00:45 31 031 Add a Default Parameter 01:27 32 032 Typing Object Literals 00:43 33 01:47 34 034 Making Object Property Types Optional 00:52 35 035 Specifying Optional Properties 00:55 36 036 A Single Source of Truth for Type Definitions 00:53 37 01:30 38 038 Add an Array to an Object 00:53 39 039 Two Syntaxes for Arrays 01:46 40 040 Arrays of Objects in TypeScript 00:48 41 041 Representing an Array of Objects 02:12 42 042 Rest Parameters in TypeScript 00:37 43 043 Using Rest Parameters in TypeScript 01:01 44 044 Tuples for Precise Array Structures in TypeScript 01:20 45 045 Using Tuple Syntax in TypeScript 01:22 46 046 Using Optional Tuple Members in TypeScript 00:50 47 047 Working with Optional Tuple Members in TypeScript 01:34 48 01:07 49 049 The Dangers of Using _any_ 02:06 50 01:25 51 051 Function Types for Type Aliases in TypeScript 01:45 52 052 Typing an Event Listener 00:46 53 01:52 54 00:50 55 02:16 56 00:52 57 01:48 58 058 Debugging JSON Parsing 00:39 59 059 Decoding the JSON.parse Error 01:20 60 060 Typing Fetch API Responses in Async Functions 01:11 61 061 Adding Types to an Async Function 02:27 62 062 Understanding How TypeScript Works in Your IDE 01:16 63 063 Introspecting Variables and Declarations in TypeScript 01:19 64 064 Hovering Over a Function Call 00:28 65 065 Fixing Errors with Hovering 01:32 66 066 Adding Documentation for Hovers 00:33 67 01:41 68 068 Manually Triggering Autocomplete 01:19 69 069 The Control + Space Shortcut 01:32 70 070 TypeScript's Approach to Errors 03:43 71 071 Quick Renaming in VS Code 01:51 72 072 Navigating Code with _Go to Definition_ 02:29 73 073 Fast Imports in VS Code 00:53 74 074 Using Autocomplete and Quick Fix to Import Variables 02:12 75 075 Organizing Imports in Large Files 00:39 76 076 The Organize Imports Hotkey in VS Code 01:12 77 077 Quick Fix Refactoring 00:54 78 078 Refactoring with Quick Fixes 01:44 79 079 Automatic Code Formatting with Prettier 02:08 80 080 Restarting the TypeScript Server in VS Code 01:17 81 081 Handling Null Values in TypeScript 01:01 82 082 Introducing Union Types in TypeScript 01:14 83 083 Diving Deeper into Unions and Assignability 00:49 84 084 Restricting Function Parameters 00:55 85 085 Combining Literal & Union Types 01:57 86 086 Literal Type Assignability 01:06 87 087 Combining Union Types in TypeScript 01:29 88 088 Create New Types By Combining Unions 01:08 89 089 How Big Can a Union Be_ 01:11 90 090 Resolving Literal Types to Wider Types 02:21 91 091 Narrowing Unions with 02:12 92 092 Conditional Narrowing in TypeScript 01:09 93 093 Different Approaches for Narrowing Inputs 02:50 94 094 Narrowing with Boolean Won't Work 01:05 95 095 Gotchas When Narrowing a Map in TypeScript 01:00 96 096 Correctly Narrowing a Map in TypeScript 01:41 97 097 Narrowing by Throwing Errors 00:59 98 098 Throwing Errors to Narrow 01:43 99 01:30 100 100 Dynamically Handling Different API Responses in TypeScript 01:41 101 101 Introducing the Unknown Type in TypeScript 02:08 102 102 Dealing with Unknown Errors in TypeScript 01:40 103 02:15 104 104 Narrowing Unknown in a Large Conditional Statement 01:16 105 105 Narrowing Unknown Types in TypeScript 02:56 106 02:24 107 107 Solving the Never Type in TypeScript 00:28 108 108 Empty Arrays and the Never Type in TypeScript 01:46 109 109 Narrowing Return Types with TypeScript 01:31 110 02:39 111 111 Narrowing in Different Scopes 01:29 112 112 Narrowing Behavior Across Scopes 04:08 113 113 Handling Separate But Related Types 01:42 114 114 Improving Type Safety with Discriminated Unions in TypeScript 04:17 115 115 Destructuring a Discriminated Union in TypeScript 00:53 116 116 Limitations of Destructuring Discriminated Unions 02:59 117 117 Narrowing a Discriminated Union with a Switch 01:05 118 118 Refactoring to a Switch Statement 02:20 119 119 The switch (true) Pattern in TypeScript 01:21 120 120 Refining Types with Discriminated Unions of Tuples 01:50 121 121 Handle Error and Success States by Narrowing 02:42 122 122 Discriminated Booleans 00:55 123 123 Discriminated Unions with Boolean Discriminators 01:09 124 124 Adding Defaults to a Discriminated Union 00:59 125 125 Handling Optional Parameters in Discriminated Unions 03:52 126 126 Should You Provide Function Return Types_ 04:51 127 127 Extending Objects in TypeScript 02:09 128 128 Use the Intersection Operator to Extend an Object Type in TypeScript 00:49 129 129 Extend an Object Using Interfaces in TypeScript 00:54 130 130 Extending Interfaces to Create Hierarchies in TypeScript 01:50 131 131 Extending Incompatible Properties 00:53 132 132 Comparing Intersections and Interface Extends 03:20 133 133 Comparing Intersection and Interface Extends in TypeScript 02:11 134 134 Allow Dynamic Keys in TypeScript Types 01:00 135 135 Dynamic Keys with Index Signatures and Record Types 03:42 136 136 Allow Any String Key while Supporting Default Properties 00:41 137 137 Add an Index Signature to an Interface 01:33 138 138 Supporting Different Types of Keys in TypeScript 01:46 139 139 Using the PropertyKey Type in TypeScript 00:51 140 140 Restricting Object Keys in TypeScript 01:09 141 141 Records and Mapped Types in TypeScript 02:52 142 142 An Issue with Duplicate Interfaces 00:51 143 143 Declaration Merging in TypeScript Interfaces 03:09 144 144 Working with Partial Data from a Type 01:37 145 145 Manage Subtypes with the Pick Utility Type 02:56 146 146 Exclude a Property from an Interface 00:50 147 147 The Omit Utility Type in TypeScript 01:29 148 148 A Quirk of Omit in TypeScript 01:49 149 149 Understanding Distributive Omit and Pick in TypeScript 03:06 150 150 Excluding Fields from a TypeScript Type 00:55 151 151 The Partial Utility Type in TypeScript 01:08 152 152 Making Type Properties Required in TypeScript 00:48 153 153 Specifying a Type with Shared Properties in TypeScript 01:24 154 154 Common Keys of Unions of Objects in TypeScript 01:28 155 155 Fixing a Type Assignment Inference Error 01:02 156 156 Inference differences between let and const 02:10 157 157 Object Property Inference 00:49 158 158 Understanding Object Properties and Assignability in TypeScript 02:44 159 159 Creating Read-only Properties 00:28 160 160 Specifying Read-only Object Properties 01:03 161 161 Using a Type Helper to Create Read-only Properties 00:52 162 162 Use the Readonly Type Helper to Create Read-Only Objects in TypeScript 00:50 163 163 Deeply Apply Read-only Properties to an Object in TypeScript 01:23 164 164 Using as const to Deeply Apply Read-only Properties to an Object in TypeScript 01:18 165 165 Comparing Object.freeze with as const 00:55 166 166 Deeply Apply Read-only Properties with as const 01:36 167 167 Prevent Array Mutation in TypeScript 00:47 168 168 Two Ways to Create Read-Only Arrays in TypeScript 01:37 169 169 Distinguishing Assignability Between Read-Only and Mutable Arrays 02:02 170 01:32 171 171 Specifying a readonly Tuple 01:54 172 172 Use the ts-reset Library to Improve Readonly Array Handling in TypeScript 02:11 173 173 Improve Type Inference for an Async Function 01:20 174 174 Two Options for Improving Promise Return Types in TypeScript 02:03 175 175 Infer Strings as Their Literal Types in Objects with as const 01:55 176 176 Classes in TypeScript 00:51 177 177 Creating a Class with Default Properties 02:46 178 178 Implement Class Methods in TypeScript 00:55 179 179 Declaring Methods in TypeScript Classes 01:31 180 180 Creating Constructors for Classes in TypeScript 00:36 181 181 Receive Arguments in Class Constructors 01:42 182 182 Getter Methods in TypeScript 01:01 183 183 Adding a Getter to a Class in TypeScript 01:42 184 184 Public and Private Properties in TypeScript 00:54 185 185 Prevent Access to Private Properties in Classes 01:54 186 186 Setter Methods in TypeScript 00:54 187 187 Add a Setter to a TypeScript Class 01:26 188 188 Extending Classes in TypeScript 01:32 189 189 Inheriting Properties from Other Classes in TypeScript 04:12 190 190 Overriding Methods in TypeScript 03:05 191 191 Ensure a Class Adheres to a Contract 00:47 192 192 Implementing Interfaces in TypeScript with Classes 02:15 193 01:10 194 02:54 195 195 Intro to TypeScript-only Features 00:53 196 196 Parameter Properties in TypeScript 01:43 197 197 Working with Enums in TypeScript 01:46 198 198 Create an Enum in TypeScript 02:51 199 199 String Enums in TypeScript 01:15 200 200 Creating a String Enum in TypeScript 02:28 201 201 Const Enums in TypeScript 04:16 202 202 Namespaces in TypeScript 02:52 203 203 Merging Namespaces in TypeScript 01:31 204 204 Declaration Merging with Interfaces Inside of Namespaces 01:15 205 205 When to Prefer ES Features to TS Features 04:43 206 206 Introduction to Deriving Types in TypeScript 00:44 207 00:58 208 208 Flowing Types with the keyof Operator 01:23 209 01:34 210 210 Combine keyof and typeof to Derive Types 02:21 211 211 No Creating Runtime Values from Types 02:04 212 212 Deriving Types with Classes 00:58 213 213 Using typeof with Classes in TypeScript 02:16 214 214 Enums as Types and Values in TypeScript 00:53 215 215 The this Keyword in TypeScript 01:38 216 216 Using the Same Name for Values and Types in TypeScript 02:10 217 217 Creating Types from Complex Function Parameters 01:38 218 218 Use the Parameters Type to Extract Function Parameters 01:39 219 219 Extracting Return Types from Functions 00:34 220 220 Using the ReturnType Type Helper 00:43 221 221 Extract the Return Type from an Async Function 00:47 222 222 Unwrap Promises with the Awaited Type Helper 01:01 223 223 Access Specific Values in an as const Object 01:22 224 224 Use an Indexed Access Type to Access a Property 02:23 225 225 Pass a Union to an Indexed Access Type 00:43 226 226 Unions and Indexed Access Types in TypeScript 01:56 227 227 Extract a Union of All Values from an Object 00:39 228 228 Pass keyof into an Indexed Access Type 02:38 229 229 Create a Union from an as const Array 01:23 230 230 Pass a Primitive to an Indexed Access Type 02:04 231 231 Required vs Unnecessary Annotations 00:42 232 232 Simplifying TypeScript Annotations 04:18 233 233 Provide Additional Information to TypeScript 01:12 234 234 The _as_ and _as any_ Keywords in TypeScript 04:11 235 235 Global Typings use any 01:08 236 236 Preventing 'any' Type Issues from Global Typings 03:18 237 237 The Limits of as in TypeScript 02:22 238 01:02 239 239 Adding a Non-null Assertion 03:16 240 240 The @ts-ignore Directive in TypeScript 03:16 241 241 The @ts-expect-error Directive in TypeScript 03:34 242 242 The @ts-nocheck Directive in TypeScript 01:47 243 243 Improve Type Annotations with the satisfies Operator 01:33 244 244 The satisfies Operator in TypeScript 02:29 245 245 Using satisfies with keyof and typeof in TypeScript 00:37 246 246 Specify Type Constraints with the satisfies Operator 01:31 247 247 Comparing as, satisfies, and Variable Annotations in TypeScript 01:30 248 248 When to Use as, satisfies, and Variable Annotations in TypeScript 04:15 249 249 The satisfies Keyword and Deeply Read-Only Objects in TypeScript 01:04 250 250 Combine as const with satisfies for Read-Only Objects 02:01 251 251 Accept Anything Except Null or Undefined 00:52 252 252 The Empty Object Type 03:03 253 253 Typing a Truly Empty Object 01:00 254 254 Handling a Truly Empty Object in TypeScript 02:45 255 255 Excess Property Warnings in TypeScript 01:08 256 256 Techniques for Triggering Excess Property Warnings in TypeScript 04:03 257 257 Excess Properties in Functions 01:11 258 258 Understanding Unexpected Properties in TypeScript 03:15 259 259 Object.keys and Object.entries in TypeScript 03:47 260 260 Iterating Over Object Keys in TypeScript 01:14 261 261 Techniques for Iterating Over Object Keys 03:42 262 262 Evolving Types using the 01:03 263 01:44 264 01:42 265 265 Function Parameter Comparisons in TypeScript 00:53 266 266 Understanding TypeScript's Function Parameter Comparisons 03:09 267 267 Typing Functions with Object Params 00:53 268 268 Typing Arrays of Functions with Object Params 01:40 269 269 Properly Typing an Object of Functions 01:48 270 270 Handling Union of Functions with Incompatible Types in TypeScript 02:13 271 271 Unions of Function Return Types 01:41 272 272 Annotating the Errors Thrown by a Function 01:13 273 273 Techniques for Annotating Errors in TypeScript 02:15 274 274 Understanding Modules and Scripts in TypeScript 02:27 275 275 Enforcing Module Usage in TypeScript 00:47 276 276 Update tsconfig for Modules 01:12 277 277 Declaration Files in TypeScript 01:40 278 278 Declaration Files Can Be Modules or Scripts 02:27 279 279 Using Declaration Files with JavaScript in TypeScript 00:57 280 280 Typing a JavaScript Module 02:29 281 281 Type Variables Declared Elsewhere 01:16 282 282 Ambient Context and the declare Keyword in TypeScript 02:32 283 283 Global Scope Declarations in TypeScript 00:58 284 284 Understanding Global Declarations in TypeScript 02:39 285 285 Configuring the lib Compiler Option 00:32 286 286 Setting a Compiler Target in tsconfig.json 05:14 287 287 DOM Typing Configuration in TypeScript 00:34 288 288 Update tsconfig.json to include DOM typings 02:16 289 289 Update DOM Typing to Include Iterable 00:39 290 290 Configuring TypeScript for DOM Iteration 01:22 291 291 Modifying TypeScript Global Scope 01:27 292 292 Adding Types to the Global Scope 02:58 293 293 Adding Type Definitions for External Libraries 00:38 294 294 Install Type Definitions from DefinitelyTyped 03:46 295 295 Integrating TypeScript with Node 01:11 296 296 Modifying process.env Typing in TypeScript 02:13 297 297 Updating Node.ProcessEnv 03:17 298 298 Types that Ship With Libraries 01:43 299 299 Declaring Module Types in TypeScript 01:01 300 300 The declare module Syntax in TypeScript 01:42 301 301 Importing and Typing Non-Code Files in TypeScript 00:59 302 302 Use Wildcards in TypeScript Module Declarations 02:29 303 303 TSConfig Options and Declaration Files 00:59 304 304 Understanding skipLibCheck in TypeScript 04:04 305 305 Should You Use Declaration Files to Store Your Types_ 02:30 306 306 Recommended Base Configuration 03:26 307 307 Understanding Isolated Modules in TypeScript 03:27 308 308 Index Access Settings 00:51 309 309 Making Code Safer with No Unchecked Indexed Access 01:30 310 310 Using TypeScript as a Linter 01:11 311 311 The noEmit Option in tsconfig.json 02:06 312 312 Module NodeNext with Extensions 04:22 313 313 The moduleResolution Option in tsconfig.json 05:08 314 314 Enforcing Import Syntax 01:07 315 315 The Verbatim Module Syntax in TSConfig 03:22 316 316 Verbatim Module Syntax Enforces Import Type 02:52 317 317 Understanding lib and target in TypeScript Configuration 03:46 318 318 Bundle Your Code for Library Use 01:20 319 319 Emitting TypeScript Declaration Files 01:05 320 320 Navigate to Source Files Instead of Declaration Files 01:04 321 321 Utilizing Declaration Maps in TypeScript 01:29 322 322 Configure JSX Support in TypeScript 00:37 323 323 Update tsconfig.json to Support JSX 02:31 324 324 Multiple TypeScript Configurations 00:39 325 325 Managing Multiple tsconfig Files 01:19 326 326 Globals are Tied to a Single Configuration 00:51 327 327 Share Configuration Across Multiple tsconfig Files 00:36 328 328 Extending a Base TypeScript Configuration 01:45 329 329 TypeScript Project References 02:38 330 330 Organizing TypeScript Configurations with Project References 06:00 331 01:14 332 332 Introduction to Generic Types 01:35 333 333 Implement a Generic Type 03:59 334 334 Generics with Multiple Type Parameters 00:51 335 335 Add Multiple Type Arguments to a Generic Type 01:52 336 336 Handle Errors with a Generic Result Type 01:57 337 337 Default Type Parameters in Generics 01:10 338 338 Specify a Default Type Parameter 01:42 339 339 Add Constraints to a Type Parameter 01:11 340 340 Constraining Type Parameters 02:46 341 341 Build a Stricter Omit Type 01:06 342 342 Constrain Keys in a StrictOmit Type Helper 01:38 343 343 Template Literal Types in TypeScript 01:03 344 344 Constrain Strings to Match a Pattern with Template Literal Types 02:10 345 345 Represent All Possible Type Combinations with Template Literals 00:38 346 346 Passing Unions to Template Literal Types 01:59 347 347 Derive Types with Mapped Types 01:04 348 348 Use a Mapped Type to Create a New Object Shape 03:21 349 349 Remapping Keys in TypeScript Map Types 01:13 350 02:28 351 351 Introduction to the Utilities Folder 01:55 352 352 Generic Functions Without Inference 01:07 353 353 Make a Function Generic 01:54 354 354 Default Parameter Types for Generic Functions 00:51 355 355 Setting a Default Parameter Type for Generic Functions 00:40 356 356 Inference in Generic Functions 01:09 357 357 Enable Generic Functions to Better Infer Types 03:39 358 358 Type Parameter Constraints with Generic Functions 01:22 359 359 Add Constraints to Generic Functions with the extends Keyword 02:45 360 360 Combining Generic Types with Generic Functions 01:16 361 361 Refactoring for Generic Types and Functions 02:15 362 362 Multiple Type Arguments in Generic Functions 01:08 363 363 Type Inference in Function Parameters 04:16 364 364 Using Type Predicates to Create Reusable Type Guards 01:26 365 365 Annotate a Return Type with a Type Predicate 03:23 366 366 Understanding Assertion Functions in TypeScript 01:35 367 367 Asserting Types with Type Predicates 02:09 368 368 Adapt a Function to Handle Different Types of Arguments 01:22 369 369 Implement Function Overloads 04:29 