To return the type of an object:

Use the [any->type] method. The following example tests whether a variable is of type array, and if so then inserts a new value to the array. Finally the result is output.

Code

local( mylocal = array('a','b','c') )

if(#mylocal->type == 'array') => {
  #mylocal->insert('d')
}

#mylocal

Result

array(a, b, c, d)