在prepareforsegue数组中不包含数据(使用swift)

Depending on what button is pressed I want to append a list of words to variable (pickedList) declared at the start. When I come to prepare for segue it overwrites what has been added and only using empty array that was added at the start. I am able to append items within the prepare for segue bit and these transfer over but this is not what I want. I am very very new to programming and have searched about a lot but can't seem to find what I am looking for. Thanks in advance!Depending on what button is pressed I want to a