goto statement in C#

Question

I'm writing a function like in C#:

public void CountNumber() 
{
       for(int i = 0; i < 40; i++) {
          if(i > 20) {
               goto out1;
          }

          Console.WriteLine("hello " + 1);

          out1:
             string hello = "";
       }
}

This basically counts the number and if the i is greater than 20 it should not write to console.writeline. it should step over and hit "out1" but the "out1" needs to have a function in the end to compile. It needs to have "string hello = """ to compile. I don't need the "string hello = """. I just want it to do nothing and got the end of the loop. Is there a way to do this without the "string hello = """ that the out1: statement needs? Like:

public void CountNumber() 
{
       for(int i = 0; i < 40; i++) {
          if(i > 20) {
               goto out1;
          }

          Console.WriteLine("hello " + 1);

          out1:
       }
}

Thanks.

Answer 1

Though it is absolutely correct to say that there are better ways to solve this problem than to use goto, I note that no one has actually answered your question.

A label must label a statement. You want to go to a location that has no statement associated with it. You can either make an empty statement with a single semicolon, or an empty block.

    out1:
    ;
} 

or

    out1:
    {}
}

But like they say, don't go there in the first place if you can avoid it.

Answer 2

This loop could easily be written many other ways - you could just loop while i<=20 instead of i<40 (best), or move the Console.WriteLine call into the if statement with the if inverted.

However, I'm assuming you're trying to work with a more elaborate scenario in your "real" case. If that's the case, instead of using goto, just use continue to skip the rest of the loop:

public void CountNumber() 
{
   for(int i = 0; i < 40; i++) {
      if(i > 20) {
         continue; // Skips the rest of this loop iteration
      }

      Console.WriteLine("hello " + 1);
   }
}

Similarly, you can use break to completely break out of the loop and not process more elements, if that's more appropriate in your real case.

Answer 3

Just invert your condition - also if...else might be an alternative. I assume there is other code otherwise you can just change the for loop itself to just count up to 20.

   for(int i = 0; i < 40; i++) 
   {
      if(i <= 20) 
      {
          Console.WriteLine("hello " + 1);
      }
      //other code
   }