title: How to reference the conents of a variable instead of a variable in Java
body: <p>Ok, I'm trying to make a quick double validator for any JTextField in a program. I would like to pass this to a function which then checks the contents of a field, makes sure it's a double, then return it as a double to the function. </p>
  
  <p>Here is what I have so far but theTF.getValue() should get the value of the string, not the string itself. </p>
  
  <pre><code>    public double valDouble(String theTF)
      {
              double theDouble;
              try
              {
                  theDouble = theTF.getValue();
                  return theDouble;
              }
      }
  </code></pre>
  
  <p>How can I run the getValue() on the contents of the string?</p>
  
  <p>Edit:
  Ok, I somewhat screwed up my meaning. I understand the parseDouble, but I left it out on accident here is what I have now:</p>
  
  <pre><code>    public static double valDouble(String theTF)
      {
          double theDouble;
          try
          {
              theDouble = Double.parseDouble(theTF);
          }
          catch(NumberFormatException e3)
          {
              theDouble = 0;
          }
          return theDouble;
  
      }
  </code></pre>
  
  <p>My Real issue is theTF represents the name of a TextField. I need the value OF the text field not the value in theTF. I'd like to have this here to, perhaps, highlight the field red etc. </p>
  
  <p><strong>Answer</strong>(Thanks Hunter):
  The best way was to pass the Object, not sure why I was trying to parse out the value of a string reference. </p>
  
  <pre><code>    public static double vDbl(JTextField theTF)
      {
          double theDouble;
          try
          {
              theDouble = Double.parseDouble(theTF.getText());
          }
          catch(NumberFormatException e3)
          {
              theTF.setText("Invalid");
              return 0;
          }
          return theDouble;
      }
  </code></pre>