title: how to combine switch and if else statements
body: <p>I'm taking an online java class and the teacher has asked for the following:
  Write a menu program that ask a user for a number indicating the four basic math equations(addition, subtraction, multiplication, division). Using a if/else structure to do the required operation, ask the user for inputs and solve the equation.
  I am new to this, but I don't see the point of the if/else, but I guess that is irrelavent.</p>
  
  <p>If I use case 1, 2, 3, 4 as below to determine the operation, how do I refference the case with a 'If statement'?</p>
  
  <pre><code>int userSelection;
  double x;        
  double y;        
  double answer;
  
  switch ( userSelection ) {
     case 1:
          TextIO.putln("Let's add! ");
          TextIO.putln();
          TextIO.putln("Enter the first number: ");
          x = TextIO.getlnDouble();
      TextIO.putln("Enter the second number: ");
          y = TextIO.getlnDouble();
          break;
  </code></pre>
  
  <p>//I thought I could use the 'If' like this</p>
  
  <pre><code>        if (case 1);  // I don't know how to refference this correctly
          answer = x + y;
          TextIO.putln( x 'plus' y 'equals' answer);
  </code></pre>
  
  <p>Thanks in advance!</p>