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The `public` modifier in TypeScript is the **most open** access level.
It makes a property or method **accessible from anywhere**:

- from inside the class,
- from its subclasses,
- and from outside, through an instance of the class.

---

## 1. Syntax

```javascript
class User {
  public name: string;

public constructor(name: string) {
    this.name = name;
  }

public greet(): void {
    console.log(`Hello, ${this.name}!`);
  }
}
```

> The `public` modifier can be **omitted**, it is the **default**.

---

## 2. Usage example

```javascript
class User {
  public name: string;
  public age: number;

constructor(name: string, age: number) {
    this.name = name;
    this.age = age;
  }

public greet() {
    console.log(`Hi, I'm ${this.name}, ${this.age} years old.`);
  }
}

const user = new User("Tim", 25);

user.name = "Alex"; // accessible
user.greet();       // accessible
```

`public` properties and methods can be freely read, changed and called **from outside the class**.

---

## 3. Access inside and outside the class

| Where you access from | Access to `public` |
|---|---|
| Inside the class | Yes |
| In a subclass | Yes |
| Outside (via an instance) | Yes |

---

## 4. The `public` modifier in constructor parameters

A shorthand declaration:

```javascript
class User {
  constructor(public name: string, public age: number) {}
}

const u = new User("Tim", 30);
console.log(u.name); // Tim
```

> TypeScript **automatically creates the fields** `name` and `age` and assigns them the passed values.

---

## 5. Everything is `public` by default

If you do not specify a modifier, the behavior is the same:

```javascript
class User {
  name: string; // this is public by default
  greet() {}
}
```

---

## 6. Comparison with other modifiers

| Modifier | Visibility | Usable outside the class? |
|---|---|---|
| **public** | Everywhere | Yes |
| **private** | Only inside the class | No |
| **protected** | In the class and subclasses | No |

---

## Summary

`public`:

- Is accessible **everywhere** (inside, outside, in subclasses);
- Is used **by default**;
- Can be placed before properties, methods and constructor parameters;
- Lets you explicitly mark a class member as **part of the class's public interface**.

---

Simple way to remember it:

> `public` = "accessible to everyone".

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