Property Chains

Property chains let you access deeply nested values in your JSON data by chaining of expressions.

Basic Chaining

To access data.Person.address.city, chain properties with of:

the __city__ of the __address__ of the **Person**

Each of steps one level deeper into the object.

Interactive Example

Reset

Policy Rule

A **Person** is local if the __city__ of the __address__ of the **Person** is equal to "London" and the __country__ of the __address__ of the **Person** is equal to "UK".

Test Data (JSON)

{ "Person": { "name": "Alice", "address": { "city": "London", "country": "UK", "postcode": "SW1A 1AA" } } }

▶ Run

Deep Nesting

Chains can go as deep as needed:

the __multiple choice__ of the __theory__ of the __scores__ of the **driving test**

This accesses data["driving test"].scores.theory["multiple choice"].

Interactive Example

Reset

Policy Rule

A **Person** passes theory test if the __multiple_choice__ of the __theory__ of the __scores__ of the **driving test** is at least 43 and the __written__ of the __theory__ of the __scores__ of the **driving test** is at least 38.

Test Data (JSON)

{ "driving test": { "scores": { "theory": { "multiple_choice": 45, "written": 42 }, "practical": { "maneuvers": 44, "traffic": 38 } } } }

▶ Run

Nested Selectors as Alternative

For accessing nested objects, you can also use nested selectors with dot notation:

__score__ of **test.theory**

This is equivalent to the __score__ of the __theory__ of the **test**, but shorter.

Tips

• Read chains right-to-left: __city__ of __address__ of **Person** means “start at Person, go to address, get city”
• Use the freely for readability — it’s ignored by the parser
• Match property names to your JSON keys (the engine handles case conversion)