title: Java: "Unexpected Type; required: Variable; found: value" by trying to return a value
body: <p>If I want to compile this on BlueJ, it throws me an "Unexpected Type; required: Variable; found: value" Error at the first "" on line 3.</p>
  
  <pre><code>public static String binaryCode(int i){
          if(i&lt;=1){
                  return "" += i%2;
          }
          return "" += i%2 += binaryCode(i/2);
  }
  </code></pre>
  
  <p>Btw, it has to be a recursion, I know a Loop would work too but it has to be solved within a recursion. The program should return the binary value as a string from an int.</p>