Классы

Создание объекта на основе класса

class Student {
    fullName; // поле класса
    age;
    marks;
}

const std = new Student();
std.fullName = "John Doe";
std.age = 20;
std.marks = [90, 80, 70, 60, 50];

console.log(std);

Методы

class Student {
    fullName; // свойство
    age;
    marks;

    sayHello() {
        console.log(`Hello`);
    }
}

const std = new Student();

std.sayHello();

this

class Student {
    fullName; // свойство
    age;
    marks;

    sayHello() {
        console.log(`Hello ${this.fullName}`);
    }

    marksAverage() {
        const sum = this.marks.reduce((acc, cur) => acc + cur, 0);
        return sum / this.marks.length;
    }

    showThis() {
        console.log(this);
    }
}

const std = new Student();

std.fullName = "Alex Smith";
std.age = 20;
std.marks = [10, 20, 30, 40, 50];

std.sayHello();
console.log(std.marksAverage());
std.showThis();

Конструктор

class Student {
    fullName; // свойство
    age;
    marks;

    constructor(fullName, age, marks) {
        this.fullName = fullName;
        this.age = age;
        this.marks = marks;
    }
}

const std = new Student("John", 20, 90);
console.log(std);

Сокращенная запись

class Student {
    constructor(fullName, age, marks) {
        this.fullName = fullName;
        this.age = age;
        this.marks = marks;
    }
}

const std = new Student("John", 20, 90);
console.log(std);

Наследование

class Person {
    constructor(name, age) {
        this.name = name;
        this.age = age;
    }

    sayHello() {
        console.log(`Hello, my name is ${this.name} and I am ${this.age} years old.`);
    }
}

const prs = new Person("John", 30);
console.log(prs);
prs.sayHello();

class Student extends Person {
    constructor(name, age, school) {
        super(name, age);
        this.school = school;
    }

    // sayHello() {
    //     console.log(`Hello, my name is ${this.name} and I am ${this.age} years old. I am from ${this.school}.`);
    // }
}

const std = new Student("John", 30, "MIT");
console.log(std);
std.sayHello();