The checkbox group, drop-down, list box and radio group fields store their options as arrays of arrays.
Array Elements
Each option in a list-type field is an array. The array contains two or three elements: the value, the display, and the group.
The value is what will be stored/saved when the form is submitted.
The display is the text that appears in the list, or next to the checkbox.
Group is used by drop-downs and list boxes to organise the options. If you don't have any groups, the options will be in a single list.
Arrays of Arrays
Because each option is an array, all of the options together are held in an array of arrays.
Example
For example, the options in the drop-down field:
Become:
COUNTY_OPTIONDATA = [
["", "Select County...", ""],
["Cornwall", "Cornwall", ""],
["Devon", "Devon", ""],
["Somerset", "Somerset", ""]
]
Note how the first array doesn't have a value. This prevents the text "Select County" being picked as an option.
Querying the Value
When you query the value of a list-type field using .queryFieldValue or the
block, it's the value you'll get back, not the display element. Be careful of this if you are displaying the value back to the user in another field or display template.