4 ms·

Any definition of polymorphism should at least mention something about the method that is invoked depends on runtime data, and is not resolved (or known) at com

• smanek 17y ago
  Yeah, Java doesn't do multimethods (i.e., method dispatch based on runtime argument types). If Class X has two methods: void foo(Object i); void foo(Integer i); then: Object test = new Integer(4); X x = new X(); x.foo(test); will invoke 'void foo(Object o);' based on the compile time type of test. Java does do dispatch based on the runtime type of X - but it is quite limiting once you are used to having proper multiple dispatch at your disposal. (caveat: not in front of a javac - this is from memory).
  • d0mine 17y ago
    You're right. It calls 'void foo(Object o);' import junit.framework.TestCase; public class TestMultimethods extends TestCase { public void test() { Object test = new Integer(4); X x = new X(); assertEquals(x.foo(test), "foo(Object)"); } } class X { String foo(Object i) { return "foo(Object)"; } String foo(Integer i) { return "foo(Integer)"; } }