For Each

For Each

Type: foreach  ·  Package: Core Activities v1.0.8

Loops through a collection —a list, an array, a dictionary, or the rows of a DataTable— and runs a block of activities once for each element. It is the loop you will use the most: “for each Excel row…”, “for each email received…”, “for each pending invoice…”.

On each pass, the current element is available in an iteration variable that you name and, if you ask for it, its position in another variable.

How it works

1. Evaluates the collection set in items.
2. For each element, stores it in the itemVariable variable (and its 0-based position in indexVariable, if you set one) and runs the activities.
3. Repeats until the collection is exhausted. With an empty collection, the body does not run and the flow continues.

What the iteration variable receives depending on items:

items is…	Each element is…
A DataTable	A row (DataRow): read its cells with str(row["Column"]).
A list or an array	The element as is (text, number, dictionary…).
A Dictionary	A pair with .Key and .Value.
A text, a number, or an empty value (null)	It cannot be iterated: the activity fails (see Common errors).

Inside the loop you can use Break (to exit early) and Continue (to skip to the next pass). The position in indexVariable keeps counting even when a pass ends with Continue, so element and position always match. Before each pass the loop checks whether the execution was terminated, so Terminate stops it between one element and the next.

Required parameters

Parameter	Type	Default	Description
items	object	—	The collection to loop through: list, array, DataTable (its rows) or Dictionary (its pairs). E.g. emails, table.
itemVariable	string	—	Name of the variable that holds the current element on each pass. E.g. item, row, email.

Optional parameters

Parameter	Type	Default	Description
indexVariable	string	—	Name of the variable that receives the current element’s position, counting from 0 (0, 1, 2…). If you leave it empty, no index variable is created.

Sub-flows

activities required

The activities that run on each iteration. They are configured as a lane on the canvas.

Output

This activity does not return a value. What it produces are the itemVariable and indexVariable variables, updated on each pass.

Example

Loop through the rows of an Excel sheet, skip the ones without an email and say which sheet row each one is on:

For Each   items = customerTable   itemVariable = row   indexVariable = n
 └─ activities:
      If    condition = isEmpty(str(row["Email"]))
       └─ then:
            Log   level = warning   message = "Row " + (n + 2) + " has no email; skipped"
            Continue          // skip this row and move on to the next one
      SMTP Send   to = str(row["Email"])   subject = "Notice"

Since n starts at 0 and row 1 of the sheet holds the headers, n + 2 is the row number a person sees in Excel.

No need to declare them

You don’t need to declare itemVariable or indexVariable in the panel: For Each creates them and updates them on each pass. Use them inside the loop, which is where the Designer recognizes them. See Iteration variables.

Looping through a table

When items is a DataTable, each element is a row (DataRow). Read its cells with str(row["Column"]) or num(row["Column"]) to handle empty cells safely. See DataRow.

The editor knows the element type

Inside the loop, the Designer infers the type of the iteration variable from items (a DataTable → DataRow, a List<int> → int, a text[] array → text, etc.). That’s why expressions over the element are validated correctly and the editor autocompletes its members as you type item.. The inference is most precise when items is a direct variable (e.g. customerTable); with complex expressions the editor falls back to a generic type.

Common errors

Message	Cause and fix
'items' is not iterable (…).	items is not a collection: it is a text, a number, or empty (null); the type received is shown in parentheses. Check that the previous activity returned a list or a table; if it can be empty, guard the loop with an If (items != null).
'itemVariable' is required.	The iteration variable name is missing. Type it in the properties panel.
'activities' is required.	The loop has no activities lane. Add at least one activity inside.
The loop does nothing	The collection is empty. Check that the previous activity returned data (for example, by logging rowCount(table) with a Log).

Related activities

• For Loop — repeat a counted number of times (when you are not looping through a collection).
• While — repeat as long as a condition holds.
• Break / Continue — control the loop from inside.