Returns the array[index] if it is valid or else returns the default value.
index( array, index, [default] )
array: (Any Type Array) A homogeneous array, whose indexed value is expected.
index: (Integer or Integer Array) The index or array of indices of the array.
default: (Any Type) The default value to be returned if the array or the index is invalid, such as if the array itself is empty or the index is < 1 or > array length.
Any Type
The type of the default value must be same as that of the elements in the array.
Retrieving a value at a single index:
index({10, 20, 30}, 2, 1)
returns 20
Return the value of a field name within a CDT where the array is the PV and the index is the field name:
index(pv!person, "firstName", "")
returns the value of the "firstName" field in a CDT of person with two fields (firstName
and lastName
)
Retrieving values at multiple indices:
index({10, 20, 30}, {1, 3}, 0)
returns 10, 30
Retrieving values at repeated indices:
index({10, 20, 30}, {1, 1, 3}, 0)
returns 10, 10, 30
Retrieving the value of a CDT field using the field name as the index argument:
index(topaginginfo(1, 10), "startIndex", 0)
returns 1
property(): This function acts as an alias to the index() function especially when applied over custom data types.