Dicts

String-keyed maps. Keys that aren't strings are converted with str().

let user = {"name": "Ada", "age": 36}
user["role"] = "engineer"     # add / update
print(user["name"])           # Ada
print(user["missing"])        # nil   (missing keys read as nil)
print(len(user))              # 3

Dot access is sugar for keys, but built-in method names take precedence:

let d = {"u": {"name": "Ada"}}
print(d.u)          # {"name": "Ada"}   (key access via dot)
print(d.keys())     # ["u"]             (method, not a key named "keys")

To read a key that collides with a method name, use d["keys"].

Iterating a dict yields its keys:

for k in {"a": 1, "b": 2} {
    print(k)        # a, then b
}

See dict methods for keys, values, has, get, remove.