Items and Expressions

A list of JSON items

Data between nodes is a list of items, and each item is an object with a json field. A node usually runs once per item. In any field you can write an expression in double curly braces: {{ $json.email }} reads a field from the current item, and {{ $("Webhook").item.json.name }} reads from an earlier node.

Items and expressions

Three items mean the next node runs three times. Expressions are JavaScript, so you can transform values inline.

Items flowing out of a node:
  [ { json: { name: "Asha", total: 1200 } },
    { json: { name: "Ravi", total: 8000 } },
    { json: { name: "Meera", total: 450 } } ]

Expressions in the next node:
  {{ $json.name }}                       -> Asha, Ravi, Meera (one run each)
  {{ $json.total * 1.18 }}               -> total with 18% tax
  {{ $json.name.toUpperCase() }}         -> ASHA, RAVI, MEERA

Check the Input panel

When an expression fails, open the node and look at the INPUT panel: field names are often different from what you assumed (Name versus name), and you can drag a field into an expression to get the exact path.

Quick check: A node receives 3 items. How many times does it normally run?

• Once for all items together
• Three times, once per item
• Never
• Exactly ten times