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Supposing the user selects the two variable declaration statements and runs Extract Method, currently (as of Eclipse 4.16M1) the refactoring is denied with the message "Ambiguous return value", as both i and s are used later in the code. public class ExtractMethod { public static void main(String[] args) { var i = 1; var s = "abc"; System.out.println(i + s); } } Using the (preview) Java 14 feature of records, doing Extract Method is feasible. This is possibly the shortest variant. public class ExtractMethod { public static void main(String[] args) { record I_S(int i, String s) {} var i_S = new I_S(1, "abc"); System.out.println(i_S.i + i_S.s); } } Another possibility. public class ExtractMethod { public static void main(String[] args) { var i_s = new I_S(1, "abc"); System.out.println(i_s.i + i_s.s); } static record I_S(int i, String s) {} } Yet another possibility, putting the record in its own file. public class ExtractMethod { public static void main(String[] args) { var i_s = new I_S(1, "abc"); System.out.println(i_s.i() + i_s.s()); } } // new file: I_S.java public record I_S(int i, String s) {}
silly question: how is this "Extract Method", i.e., where is the extracted method?
You're right in pointing out that the method is missing. I take it that you didn't mean to be rude: it's not a silly request at all, only somewhat mislabeled. The feature described in my original question could be a new refactoring called Introduce Record. Anyway, here's a possible output of Extract Method applied to the two vars in the original code where the method does make its appearance. public class ExtractMethod { public static void main(String[] args) { var i_S = i_s(); System.out.println(i_S.i + i_S.s); } static record I_S(int i, String s) {} private static I_S i_s() { var i = 1; var s = "abc"; return new I_S(i, s); } } Using Inline on both i and s in the new method gives us: private static I_S i_s() { return new I_S(1, "abc"); } ... and inlining the invocation of i_s() gives us: public class ExtractMethod { public static void main(String[] args) { var i_S = new I_S(1, "abc"); System.out.println(i_S.i + i_S.s); } static record I_S(int i, String s) {} } ... which is effectively the second version that I've listed previously.
