While gives "Found one too many { characters without a } to match it" when the same as an if statement does not

Question

When the following code is run it won't compile and I get an error telling me, "Found one too many { characters without a } to match it.".

while (thePlayer.position.x > thePlayer.position2.x - 60) { 
              println("x2 =" + thePlayer.position2.x);
              thePlayer.position.x = thePlayer.position.x - 1;
              println("x =" + thePlayer.position.x);
            }
            else {
              thePlayer.position2.x = thePlayer.position.x;
              println("complete");
            }

However, when I change it to the sample below (an if statement) it compiles fine and runs through where the only change is substituting 'while' for 'if'.

if (thePlayer.position.x > thePlayer.position2.x - 60) { 
              println("x2 =" + thePlayer.position2.x);
              thePlayer.position.x = thePlayer.position.x - 1;
              println("x =" + thePlayer.position.x);
            }
            else {
              thePlayer.position2.x = thePlayer.position.x;
              println("complete");
            }

I'm really confused by this...

Answer 1

There is no while..else construct in Java (although Python has one and it's rather nifty).

So, there are two possibilities depending on what you're actually trying to achieve.

First, if you want the else block to run regardless of the while block, simply place it afterwards:

while (thePlayer.position.x > thePlayer.position2.x - 60) { 
    println("x2 =" + thePlayer.position2.x);
    thePlayer.position.x = thePlayer.position.x - 1;
    println("x =" + thePlayer.position.x);
}
thePlayer.position2.x = thePlayer.position.x;
println("complete");

That will loop until the condition becomes false then execute the remaining code.

On the other hand, if you want the else block to run only if the while block didn't run (mimicking Python's while..else construct), that requires something like a while-within-if setup:

if (thePlayer.position.x > thePlayer.position2.x - 60) { 
    while (thePlayer.position.x > thePlayer.position2.x - 60) { 
        println("x2 =" + thePlayer.position2.x);
        thePlayer.position.x = thePlayer.position.x - 1;
        println("x =" + thePlayer.position.x);
    }
} else {
    thePlayer.position2.x = thePlayer.position.x;
    println("complete");
}

There, the else clause only executes if the while loop ran one or more iterations.

You just need to select the behaviour you want and choose one of the options above.

Answer 2

You can't have an else statement without an if statement. Change:

while (thePlayer.position.x > thePlayer.position2.x - 60) { 
              println("x2 =" + thePlayer.position2.x);
              thePlayer.position.x = thePlayer.position.x - 1;
              println("x =" + thePlayer.position.x);
            }
            else {
              thePlayer.position2.x = thePlayer.position.x;
              println("complete");
            }

to:

while (thePlayer.position.x > thePlayer.position2.x - 60) {
  println("x2 =" + thePlayer.position2.x);
  thePlayer.position.x = thePlayer.position.x - 1;
  println("x =" + thePlayer.position.x);
}

thePlayer.position2.x = thePlayer.position.x;
println("complete");

This will run the loop and when the condition becomes false it will run the lines after the while loop.

Answer 3

Thats because an 'else' after a while loop is wrong syntax. This will work:

while(thePlayer.position.x >      thePlayer.position2.x - 60)
{
println("x2 ="   thePlayer.position2.x);
thePlayer.position.x = thePlayer.position.x - 1;
println("x ="   thePlayer.position.x);
}

thePlayer.position2.x = thePlayer.position.x;
println("complete");

Hope this helps.....