Fact is Germany did build or attempted to build 3 aircraft carriers the K.M Graf Zeppelin, K.M Peter Stresser and the K.M Paul von Hindenburg, according to Janes the K.M Graf Zeppelin was complete and according to various sources Reichsmarschall Herman Goering refused to divert aircraft to the ship.

I have read also that the K.M Peter Stresser was in advance state of construction about 40% and the K.M Paul von Hindenburg had her keel laid but later the two ships were broken up and the steel was diverted to U-Boat construction.

But be that as it may even if Germany had at least these three ships they would never have been used as Hitler would have protected them, they in the end would be expensive white elephants.