I know this sounds ridiculous but I am seriously confused now.
Basically I have two vars, one is [Data]
and one is Array<Data>?
I need to combine these two.
I've tried do var1+var2
, which is giving me errors say can't do binary operations on these two.
So I googled, I can use append method, now there comes more questions:
- the append method is crossed out in autofill, so I am not sure if I should use it.
- Even if I try to use it (while it's being crossed out), it is still giving me errors
Here is the code and errors I get:
var a1:[Data] //a return value from other function
var a2:Array<Data>? //a parameter that's passed in
a1.append(contentsOf:a2) //Cannot use mutating member on immutable value: function call returns immutable value
a1+a2 //Binary operator '+' cannot be applied to operands of type 'Array<Data>' and 'Array<Data>?'
Both arrays can be empty, how can I concatenate these two arrays?