An associative array maps unique keys to values that can be non-unique. An associative array is also called a dictionary, a map, a hash map, or a hash table.
Note the following about keys:
• Keys are placed in quotes.
• The value associated with a key can be a number, date, matrix, list, and so on.
• A key cannot be a floating point number. Only integers are supported.
• You can use matrices as both keys and values, or lists as both keys and values, but you cannot mix the two. In other words, you cannot use a matrix as a key and a list as a value, or the other way around.
• Though associative arrays are not usually ordered, in JMP, keys are returned in alphanumeric order for the purpose of iteration and serialization.
For very large lists, using an associative array is more efficient and faster.