To add a value between the values in a string array

I want to put a space between each string like the bottom, but I don't know what to do Elements can be reduced and stretched.
Help me, masters!

van = ["Ga"]

//The desired result ["Ga", "Na", "Da"]


Varm = ["Ga" "Na" "Da" "La" "Ma"]

//The desired result ["Ga", "Na", "Da", "La", "Ma"]