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For Loops

For loops iterate over each item in a collection, executing a block for each.

Why this exists​

For loops simplify processing collections like arrays or objects without manual indexing.

How it works​

Use for followed by a variable name, in, the collection, then the block. The variable takes the value of each item in turn.

Examples​

Iterating over an array:

set numbers = [1, 2, 3, 4, 5]
for num in numbers {
  print(num * 2)
}

Iterating over an object (keys):

set person = {name: "Alice", age: 30}
for key in person {
  print(key + ": " + person[key])
}

Common mistakes​

  • Attempting to modify the collection during iteration.
  • Using the loop variable outside the loop (it may not be defined).
  • Forgetting that for iterates over keys for objects, not values.