interfaces, classes, arrays

src/index.ts

@@ -1 +1,120 @@
-console.log('Hello world!')
+interface People {
+    name: string;
+    age: number | undefined;
+}
+
+let people01: People = {
+    name: "Kostya",
+    age: undefined
+};
+
+let people02: People = {
+    name: "Yura",
+    age: 32
+}
+
+people01.age = 60;
+// console.log(people01);
+// console.log(JSON.stringify(people01));
+// console.log(people01.age);
+console.log(`${people01.name} имеет возраст ${people01?.age ?? '40'}`); //Kostya --- 60
+console.log(`${people02.name} имеет возраст ${people02?.age ?? '40'}`); //Yura --- 32
+console.log(`${people01.name} имеет возраст ${people02?.age ?? '40'}`);
+
+interface PeopleLocation extends People {
+    location: string;
+}
+
+let peopleLocation01: PeopleLocation = {
+    name: "djdf",
+    age: 42342,
+    location: "dafdf"
+}
+class ProcessingPeoples implements PeopleLocation {
+    name: string;
+    age: number | undefined;
+    location: string = '';
+
+    constructor(name: string){
+        this.name = name;
+    }
+}
+
+class ProcessingPeoplesExt extends ProcessingPeoples {
+    isActive: boolean = false;
+
+    constructor(name: string, isActive: boolean){
+        super(name);
+        if(isActive) {
+            this.location = 'Gorkyi street';
+        }
+        else{
+            this.location = '';
+        }
+    }
+}
+
+let a: ProcessingPeoples = new ProcessingPeoplesExt("Vasya", true);
+
+class Duck {
+    type: string = 'Duck';
+    weight: number = 0;
+    log(){
+        console.log("I'm simple duck");
+    }
+}
+
+interface Eateable {
+    eat(): void;
+}
+
+class GreyDuck extends Duck implements Eateable{
+    constructor() {
+        super();
+        this.type = 'GreyDuck'
+    }
+    override log(){
+        console.log("I'm grey duck");
+    }
+
+    eat(){
+        console.log("I'm eat");
+    }
+}
+
+class RedDuck extends Duck implements Eateable {
+    constructor() {
+        super();
+        this.type = 'RedDuck'
+    }
+    eat(): void {
+        console.log("I'm eat");
+    }
+    override log(){
+        console.log("I'm red duck");
+    }
+}
+
+let duck1 = new RedDuck();
+let duck2 = new GreyDuck();
+
+let array: Eateable[] = [
+    duck1,
+    duck2
+];
+
+for (let item of array) {
+    item.eat();
+}
+
+let array2: Duck[] = [
+    duck2,
+    duck1
+];
+
+for (let item of array2) {
+    item.log();
+}
+
+array2.filter(item => "eat" in item);
+