The
HashMap.length function returns the number of keys at a specific location in the
HashMap. Each
key_value argument must be a numeric or string expression matching the type specified when
declaring the HashMap. If no arguments are provided, the number of first-dimension keys is returned; if one argument is provided, the number of second-dimension keys is returned; and so on.
The function returns the number of keys or 0 if no keys exist at the specified location.