# get\_attr

### Description

`get_attr` gives you access to named properties of an [instance](https://docs.atfinity.io/guides/glossary/instance) using [expressions](https://docs.atfinity.io/rule-language/expressions).

This is useful if the characteristics (properties) of an instance need to play a role in determining the next step in a [process](https://docs.atfinity.io/guides/glossary/process).

If a property doesn’t exist, you can choose to have a default value assigned to it.<br>

### Example

```
p is Person
get_attr(p, "age", 16) >= 18
```

atfinity dives in and looks up what the value of the attribute “age” is for the person in this [case](https://docs.atfinity.io/guides/glossary/case). If “age” is 18 or higher, this condition evaluates to true.

If “age” has not been provided, or “age” is not even a property of a person, the default value ‘16’ will be used. This means the condition ‘greater than or equal to 18’ evaluates to fals&#x65;**.**<br>

We can also use an expression to choose which property to access.&#x20;

```
p is Person
get_attr(p, "favourite_property")
```

Here, the system takes what a user has entered as `favourite_property` to work with. If that property does not exist, the condition evaluates to ‘unknown’.