> For the complete documentation index, see [llms.txt](https://docs.rulecube.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.rulecube.com/v2.5/how-to-guides/ruleset-development/entities/entity-instantiation.md).

# Entity instantiation

Anywhere in code (functions, rules, calculated properties), you can create new entities on the fly. For instance, when you have an Entity named 'Person', you can create an instance like this: `new Person()`

A few examples:

```js
// Inside a Function
let person = new Person();
person.FirstName = "John";
person.LastName = "Doe"
return person;
```

alternatively:

```js
let person = new Person({ FirstName: "John", LastName: "Doe"});
return person;
```

Calculated properties work as expected. Assuming Person has a calculated property named 'FullName' that combines the first and last name properties:

```js
let person = new Person({ FirstName: "John", LastName: "Doe"});
return person.FullName; // "John Doe"
```


---

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