Question: I'm trying to serve API with ***nodeJS***, and database use ***oracle***. I've an object like this that I got from `req.body.detail`: 

```
{ 
    title: "How to Have", 
    content: "<ol><li><b>Lorem ipsum dolor sit amet.</b></li></ol>"
} 

```

then I do 

```
const data = JSON.stringify(req.body.detail);

```

but the inserted data in table become doesn't has *escape string*, it become likes:

```
{"title":"How to Have","content":"<ol><li><b>Lorem ipsum dolor sit amet.</b></li></ol>}

```

How do I can escape string to whole object and result become like this:

```
{"title":"How to Have","content":"<ol><li><b>Lorem ipsum dolor sit amet.<\/b><\/li><\/ol>}

```

My column in table has datatype `clob`.

Answer: 
If

`public class ClassName1 extends/implements ClassName`

than it is perfectly valid.

This is how polimorphism works - you can treat given instance as it would be a solely instance of any of its superclasses or interfaces it implements.
`ClassName` is the type of the variable `a`, which means for your problem, that `a` can represents an object of the type `ClassName` (and any other subclass of it).

So, the sentence `ClassName a = new ClassName1()` only make sense and is right if the `ClassName1` is a subclass of `ClassName`.