Loops

Use loop collection as value for one binding or loop collection as key, value for two.
continue skips the rest of the current iteration; break exits the nearest loop.
Do not structurally mutate the collection being iterated.

Looping An Array

code

1number total = 023loop expenses as expense {4  total = total + expense.amount5}

The one-binding form receives each element. The two-binding form receives the numeric index first and the element second. Both bindings are local to the loop body.

Looping A Map

code

1number room_total = 023loop balances.entries() as member_id, amount {4  room_total = room_total + amount5}

For maps, the first binding is the string key and the second is the typed value. entries() keeps the same map value while making the key-and-value intent explicit.

Continue And Break

code

1number open_total = 023loop expenses as expense {4  if expense.status == ExpenseStatus.Settled {5    continue6  }78  if open_total >= 500 {9    break10  }1112  open_total = open_total + expense.amount13}

continue skips statements below it and begins the next iteration.
break exits the nearest enclosing loop.
Both keywords are only valid inside a loop.

Choose A Loop Or Collection Method

Goal	Prefer
Produce a filtered array	`filter`
Project every item to another value	`collect`
Check any or all items	`any` or `all`
Accumulate a total or perform several statements per item	`loop`
Need early exit	`loop` with `break`
Need to skip selected items while doing other work	`loop` with `continue`

Mutation Safety

code

1Expense[] open_expenses = []23loop expenses as expense {4  if expense.status != ExpenseStatus.Settled {5    open_expenses.push(expense)6  }7}

Common Mistakes

Wrong	Correct
`for expense in expenses`	`loop expenses as expense`
`foreach expenses`	`loop expenses as expense`
`while condition`	Use a collection loop or restructure the workflow.
`break` outside a loop	Return, throw, or use a conditional as appropriate.

Continue Learning

Collections Choose between loops and typed collection methods.Functions Return accumulated results from reusable behavior.