# Inheritance

Like all object-oriented programming languages, Lua++ supports full class inheritance. To inherit all the heritable properties of a class in Lua++, one would separate the class name from the base class using a colon in this way: `tag : base-class`, and for multiple class inheritance, one would separate each base class with a comma: `tag: base-1, base-2, ...` as shown in the following example:

```typescript
class Person {
    firstName: string,
    lastName:  string,

    constructor(firstName: string, lastName: string)
        self.firstName = firstName
        self.lastName = lastName
    end,

    function getName(): string
        return self.firstName .. " " .. self.lastName
    end,

    function getDescription(): string
        return "This is " .. self.getName() .. "."
    end
}
```

Here we define a base class `Person`, with the `firstName` and `lastName` properties. This class has two public methods, `getName()`, and `getDescription()`. As mentioned earlier, to inherit a class you use the `:` operator. For example, the following `Employee` class inherits properties and methods from the `Person` class:

```typescript
class Employee : Person { 
    
}
```

Since the `Person` class has a constructor that initializes the `firstName` and `lastName` properties, you need to initialize these properties in the constructor of the `Employee` class by calling its parent class’ constructor. This can be done by using the `base()` keyword.

```typescript
class Employee : Person {
    job: string,    
 
    constructor(firstName: string, lastName: string, 
                job: string)
        self.job = job
        
        -- Call the constructor of the person class
        base(firstName, lastName)
    end
}
```

The following creates an instance of the `Employee` class which inherits all the methods and properties of the `Employee` class:

```lua
local employee: Employee = Employee("Max", "Prihodko", "Programmer")
```

Lua++ also allows you to override methods inherited by a base class. This can be done by using the `:` symbol after the name definition of the class.

```typescript
class Employee : Person {
    job: string,    
 
    constructor(firstName: string, lastName: string,
                job: string)
        self.job = job
        
        -- Call the constructor of the person class
        base(firstName, lastName)
    end,

    function describe(): string
        return base.describe() .. " I am a " .. 
                                    self.job .. "."
    end
}

local employee: Employee = Employee("Max", "Prihodko",
                                    "Programmer")

print(employee.describe())
```

The output of this fragment of code will be:

```
This is Max Prihodko. I am a Programmer.
```