Merge branch '04_02' into 04_03

1-working-with-generics/1-1-generics/ElementHolder.ts

@@ -25,3 +25,13 @@ export class ElementHolder<T> implements Printer<T> {
     this.values = this.values.filter(v => v !== value);
   }
 }
+
+
+const holder = new ElementHolder<string>(["hello", "world", "typescript"]);
+holder.printAll();  // This will print "hello", "world", "typescript"
+
+holder.add("new element");
+holder.printAll();  // Now prints "hello", "world", "typescript", "new element"
+
+holder.remove("world");
+holder.printAll();  // Now prints "hello", "typescript", "new element"

1-working-with-generics/1-1-generics/KeyValuePair.ts

@@ -13,3 +13,6 @@ class KeyValuePair<K, V> {
     console.log(`Key: ${this.key} - Value: ${this.value}`);
   }
 }
+
+let pair = new KeyValuePair<string, string>("url", "something.com");
+pair.displayPair();

1-working-with-generics/1-1-generics/Response.ts

@@ -4,6 +4,16 @@ export interface Response<T> {
   data: T;
 }
 
+function createResponse<T>(status: number, message: string, data: T): Response<T> {
+  return { status, message, data };
+}
+
+const stringResponse = createResponse<string>(200, "OK", "This is a successful response");
+console.log(stringResponse);
+
+const numbersResponse = createResponse<number[]>(200, "OK", [1, 2, 3, 4]);
+console.log(numbersResponse);
+
 
 
 

1-working-with-generics/1-1-generics/exampleWithGenerics.ts

@@ -3,6 +3,9 @@ function printSomething<Type>(arg: Type): Type {
   return arg;
 }
 
+let someValue = printSomething<string>("something");
+// let someValue2 = printSomething<string>(3);
+let someValue3 = printSomething("some other thing");
 
 function printSomething2<T, U, V>(arg1: T, arg2: U): V {
   // some body that logically results in a value of type V

1-working-with-generics/1-1-generics/exampleWithoutGenerics.ts

@@ -1,4 +1,4 @@
 function printSomething3(arg: string): string {
   console.log(arg);
   return arg;
-}
+}

1-working-with-generics/1-2-advanced-generic-patterns/exampleConstraint.ts

@@ -2,8 +2,22 @@ function logLength<T extends { length: number }>(item: T): void {
   console.log(item.length);
 }
 
+logLength("Hello TypeScript");
+logLength([2]);
+
 
 
 function processSerializable<T extends { serialize: () => string }>(item: T) {
   console.log(item.serialize());
 }
+
+class User {
+  constructor(public name: string, public age: number) {}
+
+  serialize(): string {
+    return JSON.stringify({name: this.name, age: this.age});
+  }
+}
+
+const user = new User("Dione", 35);
+processSerializable(user);

1-working-with-generics/1-2-advanced-generic-patterns/exampleDefaultValue.ts

@@ -5,3 +5,7 @@ class SomeList<T = string> {
     this.list.push(t)
   }
 }
+
+const stringList = new SomeList();
+stringList.add("TS");
+stringList.add("is cool");

1-working-with-generics/1-2-advanced-generic-patterns/useAppConfig.ts

@@ -10,3 +10,6 @@ const appConfig: AppConfig = {
   logLevel: 'info',
   port: 3000
 };
+
+const debugStatus = getConfigValue(appConfig, 'debug');
+const appPort = getConfigValue(appConfig, 'port');

1-working-with-generics/1-3-design-patterns-generics/document-example/usingDocumentFactory.ts

@@ -0,0 +1,16 @@
+import { DocumentFactory } from "./DocumentFactory";
+const factory = new DocumentFactory();
+
+const wordDoc = factory.createDocument("word");
+wordDoc.content = "Hello, the bird is the word";
+wordDoc.printContent();
+
+const excelDoc = factory.createDocument("excel");
+excelDoc.content = "Data1, Data2, Data3";
+excelDoc.printContent();
+
+try {
+  const pdfDoc = factory.createDocument("pdf");
+} catch(error) {
+  console.log(error);
+}

2-advanced-types/2-1-utility-types/Todo.ts

@@ -8,5 +8,7 @@ type TodoPreview = Pick<Todo, "title" | "completed">;
 
 const todoPreview: TodoPreview = {
   title: "Finish article",
-  completed: false,
+  completed: false
 };
+
+

2-advanced-types/2-1-utility-types/User.ts

@@ -9,4 +9,4 @@ const user: Readonly<User> = {
 };
 
 // Error: Cannot assign to 'name' because it is a read-only property.
-user.name = "Marya A";
+// user.name = "Marya A";

2-advanced-types/2-1-utility-types/exampleRecord.ts

@@ -6,4 +6,4 @@ const userStatus: Record<number, Status> = {
   3: "pending",
 };
 
-console.log(userStatus[1]); // Output: "active" (video)
+console.log(userStatus[1]); // Output: "active" 

2-advanced-types/2-1-utility-types/otherExamples.ts

@@ -1,4 +1,41 @@
 type AvailableDrinks = "Coffee" | "Tea" | "Water" | "Soda";
 type NonCaffeinated = Exclude<AvailableDrinks, "Coffee" | "Tea">;
 
+type SomeDrinks = Extract<AvailableDrinks, "Coffee" | "Tea" >;
 
+type MaybeString = string | null | undefined;
+type JustString = NonNullable<MaybeString>;  // string 
+
+function getString() {
+  return "hello";
+}
+
+type MyString = ReturnType<typeof getString>;  // string
+
+class MyClass {
+  x: number;
+  y: number;
+
+  constructor(x: number, y: number) {
+    this.x = x;
+    this.y = y;
+  }
+}
+
+type ConstructorParams = ConstructorParameters<typeof MyClass>;  
+
+type MyInstance = InstanceType<typeof MyClass>;  // MyClass
+
+function greet(name: string, age: number) {
+  console.log(`Hello ${name}, you are ${age} years old.`);
+}
+
+type Params = Parameters<typeof greet>;  // [string, number]
+
+function fn(this: string, age: number) {
+  console.log(this.toUpperCase());
+}
+
+type ThisParamsType = ThisParameterType<typeof fn>;  // string
+
+const fnWithoutThis: OmitThisParameter<typeof fn> = fn.bind("Hello"); 

2-advanced-types/2-2-mapped-types/Person.ts

@@ -1,4 +1,4 @@
-export interface Person {
+export type Person = {
   name: string;
   age: number;
 }

2-advanced-types/2-2-mapped-types/optionalPerson.ts

@@ -4,3 +4,7 @@ type OptionalPerson = {
   [Property in keyof Person]?: Person[Property];
 }
 
+const person: OptionalPerson = {
+  name: "Maryam",  // 'age' is now optional thanks to the mapped type
+};
+

2-advanced-types/2-2-mapped-types/readOnlyPerson.ts

@@ -1,10 +1,12 @@
 import { Person } from './Person';
 
 type ReadonlyPerson = {
-  [Property in keyof Person]: Readonly<Person[Property]>;
-}
+  readonly [Property in keyof Person]: Person[Property];
+};
 
 const readPerson: ReadonlyPerson = {
   name: "Adnane",
   age: 38
 };
+
+// readPerson.name = "Another name"; // Read only, so not allowed

2-advanced-types/2-2-mapped-types/stringifiedPerson.ts

@@ -6,5 +6,5 @@ type StringifiedPerson = {
 
 const stringPerson: StringifiedPerson = {
   name: "Pradeepa",
-  age: "30"  // Note: 'age' is now a string
+  age: "30" // Note: 'age' is now a string
 };

3-mastering-function-overloading/3-2-practical-use-case/log.ts

@@ -0,0 +1,17 @@
+function log(message: string): void;
+function log(error: Error): void;
+function log(message: string, error: Error): void;
+function log(param1: string | Error, param2?: Error): void {
+  if (typeof param1 === 'string' && param2 instanceof Error) {
+    console.error(`Error: ${param1}`, param2);
+  } else if (param1 instanceof Error) {
+    console.error(param1);
+  } else {
+    console.log(param1);
+  }
+}
+
+// Usage
+log("User login successful.");
+log(new Error("Failed to connect to database."));
+log("User request failed.", new Error("Session timeout"));

3-mastering-function-overloading/3-2-practical-use-case/userExample.ts

@@ -0,0 +1,29 @@
+interface User {
+  id: number;
+  username: string;
+  email: string;
+}
+
+function getUser(id: number): User;
+function getUser(username: string): User[];
+function getUser(id: number, username: string): User;
+function getUser(param1: number | string, param2?: string): User | User[] {
+  if (typeof param1 === 'number' && param2) {
+    // Fetch user by ID and username
+    console.log(`Fetching user by ID: ${param1} and username: ${param2}`);
+    return { id: param1, username: param2, email: "[email protected]" }; // Simulated data
+  } else if (typeof param1 === 'number') {
+    // Fetch user by ID
+    console.log(`Fetching user by ID: ${param1}`);
+    return { id: param1, username: "user123", email: "[email protected]" }; // Simulated data
+  } else {
+    // Fetch users by username
+    console.log(`Fetching users by username: ${param1}`);
+    return [{ id: 1, username: param1, email: "[email protected]" }]; // Simulated data
+  }
+}
+
+// Usage
+console.log(getUser(10));
+console.log(getUser("john_doe"));
+console.log(getUser(10, "john_doe"));