Enterprise Architect project programming language
In Enterprise Architect when I model a class and specify the implementation language of the class, then use an instance of the class in a use case, the implementation language of the instance in the use case is not the implementation language of the class, but is the default. Is there a way to make Enterprise Architect use the set implementation language of the class for the implementation language of all instances of that class?
Answer
There isn't an option to make instances follow the class language (but that's a good suggestion to send to Sparx), but you can set the default language for all new elements. From your question, I take it you already know how but I'll include it for other readers.
Tools - Options - Source Code Engineering - Default Language for Code Generation is the one you're after. This option is somewhat incorrectly named; it actually sets the default language for created elements.
As long as you're modelling things for one implementation language at a time this works very well. If you're modelling for different languages and realize that you've got the wrong one in a large part of your model, you can right-click the package in the project browser and select "Code Engineering - Reset Options for this Package."
Select "Where language is" - Any, and "Convert to" the language you want. Make sure to tick "Process Child Packages."