I need help with the eval() function of javascrit

You can use eval() like this:

JS:

     private var code:String = "print (a + b)";
     var a:int = 3;
     var b:int = 2;
     var printOnUpdate:boolean = false;
     
     function Start ()
     {
         code = "print ('invoked from start: '+ (a - b) )";
         eval(code);
     }
     
     function Update ()
     {
         if(printOnUpdate)
         {
             code = "print ('invoked from update: '+ (a * b) )";
             eval(code);
             printOnUpdate = false;
         }
     }
     
     function OnGUI()
     {
         if (GUI.Button (Rect (150, 10, 100, 50), "evaluate"))
         {
             code = "print ('invoked from OnGUI: '+ (a + b) )";
             eval(code);
             a++;
             printOnUpdate = true;
         }
     }
  (expanding on Eric5h5s example in another thread)

Notice that only the string-var "code" can be private. Every var that is accessed in the evaluated function (in this case ints "a" and "b") have to be public, otherwise you will see the described errormessage. The string "code" can be changed at any point, as you see in the example, and just as well you can change a or b.

Also notice that "#pragma strict" has to be removed in any script where eval() is used. If enabled for any script in which you access eval() it will throw the error, and not only for that script, but for ALL scripts in which you use eval() (even those that already have the pragma-line removed!)