# ischosen

This function returns the value true if and only if the data object reference specifies the variant of the union type that is actually selected for a given data object.

Related keyword:

- boolean
- true
- false
- union

### ischosen(any_type value) return boolean

Example 1:

type union MyUnion
{ PDU_type1 p1,
PDU_type2 p2,
PDU_type p3
}

...

// and given that MyPDU is a template of MyUnion type
// and received_PDU is also of MyUnion type
// then
MyPort.receive(MyPDU) -> value received_PDU
ischosen(received_PDU.p2)
// returns true if the actual instance of MyPDU carries a PDU of the type PDU_type2