为什么它不让我在 java 中将字符串连接到整数？

Question

So, I have this for loop, at the end of which I attempt to concatenate an integer to a string to an integer, like so:

int a = 0;
for (int i = 0; i < userResponses.length; i++)  {
    if (userResponses[i].equals(correctAnswers[i]))
       a++;
    return a + ("/") + correctAnswers.length;
}

It gives me an incompatible types error. That seems really weird as I thought Strings and ints could be concatenated. Here's the exact error:

TriviaTest.java:51: error: incompatible types
     } return a + ("/") + correctAnswers.length;
                        ^
  required: int
  found:    String
  1 error

From what I observe, the problem is with the return statement.

Answer 1

There is nothing wrong with the concatenation expression itself. It would work if you printed it, for example. It sounds very much like your method's return type is int , so it can't return a String.

Also it looks a bit strange where you seem to have the return statement unconditionally in the loop.