# object · Rell standard library · Chromia Docs (concept)

> hidden abstract type object Parent of all object types. An object is a singleton data structure that resides in the SQL database. Objects are much like ent

Source: https://docs.chromia.com/pages/rell-stdlib/-rell-system-library/root/object/

TYPE

# object

```signature
hidden abstract type object
```

Parent of all object types. An object is a singleton data structure that resides in the SQL database.

Objects are much like entities, with the following restrictions:

* only a single instance is allowed for each definition
* all object attributes must have default values
* object values cannot be created or deleted from code (they are automatically created during blockchain
  initialization)

Example definition:

Rell

```
object state {
    mutable x: integer = 0;
    mutable s: text = 'n/a';
}
```

Object attributes are accessed directly:

Rell

```
print(state.x);
print(state.s);
```

Object values can be modified directly, or with an `update` statement:

Rell

```
// Direct modification
state.x += 10;
state.s = 'Updated';
// Modification via update statement
update state ( x += 5, s = 'Updated' );
```

**See Also**

1. [`@` operator - Chromia Documentation](https://docs.chromia.com/rell/language-features/database/overview/#-operator)

Since 0.7.0

[View this page on docs.chromia.com](https://docs.chromia.com/pages/rell-stdlib/-rell%20-system%20-library/%5Broot%5D/object/index.html)Generated API reference, mirrored from the live docs