JSON Length

JSON Length measures the size of a JSON structure. For arrays, it returns the number of elements. For objects (including OrderedJSON), it returns the number of keys. The Is Empty output provides a quick boolean check for zero-length structures.

If the input is not a JSON object or array (for example, a string, number, or null), Length returns 0 and Is Empty returns true.

Array length:

Input: [10, 20, 30, 40]

Length: 4, Is Empty: false

Object key count:

Input: {"x": 1, "y": 2, "z": 3}

Length: 3, Is Empty: false

Empty array:

Input: []

Length: 0, Is Empty: true

Empty object:

Input: {}

Length: 0, Is Empty: true

Non-structure input:

Input: "hello" (string, not a JSON structure)

Length: 0, Is Empty: true

• Checking if incoming data is empty before processing
• Driving loop counters based on array size
• Monitoring data stream health — detect when a source stops sending data
• Conditional logic based on whether a collection has content

• Use Is Empty for simple guard checks in your graph logic, rather than comparing Length to 0 with a Compare node.
• For arrays, Length equals the value you would get from JSON Array's Length output.
• For objects, Length equals what JSON Keys would report as Count.
• This node works with both plain dictionaries and OrderedJSON objects.