Loop: repeat for every item

In the portal, under Environments, click Development and there Open; Flow opens in a new tab. There, click ＋ next to General, choose New workflow and give it a name. A new workflow starts with an Event trigger: the point where it begins.

Put an order with a list of lines under the trigger's Sample data (Code). A list is between [ ].

Add Transform data with a field total = 0. That is the counter the loop adds to in a moment; without a starting value the field does not exist on the first pass.

Choose Loop in the library. Under Which list you type the name of the list (without {{ }}), and you give the current item a name: line. In the steps inside the loop you read the item as {{line.price}}.

At the bottom of the loop, choose Transform data under Add step: it lands in the loop's area and runs for every line. Set total to = round(total + line.quantity * line.price, 2): the previous total plus this line.

Select the steps (click the first, and the others while holding Shift) and click Align horizontally: they then stand in one line and you read the workflow from left to right; a branch (such as No of an If / Else) gets its own row below. Fit to view puts everything in sight; then Save.

At the bottom you see every pass with the item whose turn it was, and at the end how often the loop ran. After the loop, total is the amount of all lines together; the item line no longer exists then.