Never.
No , not yet
bosnia was once part of yugoslavia. yugoslavia had a socialist government. in the early to mid 1990's their was a violent civil war which led to yugoslavia dividing into five countries; Slovenia, Croatia, Serbia, Macedonia, and Bosnia and Herzegovina. so yes bosnia was once part of the socialist union of yugoslavia.
Yes, as part of the now dissolved Republic of Yugoslavia, from 1945 to 1992.
Yugoslavia does not exist. Croatia was part of that country.
Bosnia and Herzegovina and Croatia were formerly part of Yugoslavia (full name Socialist Federal Republic of Yugoslavia) until declaring independence in 1992.
No.
it was part of socialist Yugoslavia, so yes
Full name of Macedonia is Former Yugoslav Republic of Macedonia, so Macedonia was a part of Yugoslavia. Slovenia was also a part of Yugoslavia. Slovakia however was not a part of Yugoslavia, but it was a part of Czechoslovakia, both of them were communist countries after WW2.
nope
never was a part
Yugoslavia no longer exists. It was not part of the European Union when it did exist. It broke up into a number of countries. Slovenia and Croatia are two countries that were part of Yugoslavia and are now members of the European Union.