Does this if statement work correctly?

Programming Questions

Alex Pilk..

Does this if statement work correctly?

in Programming Questions • 4 months ago

Just wanna make sure if my function does what I think it does.

I think that if statement at line 4 or 5 is true, loop starts over. And if the loop ends and these statement at line 5 has never been false function returns true. Am I right?:

boolean myFunction(int exeption){
for(int i=0; i<whatever.length; i++){
if(i==exeption){} else
if (thisstatementistrue) {/*increment i and loop again*/} else {return false;}
}
return true;
}

Replies(5)

GoToLoop

Re: Does this if statement work correctly?

4 months ago

Your example is a little senseless, w/ all those empty blocks when if () is true!

Anyways, in my understanding, this function will only return false when the passed parameter:

( exeption >= whatever.length) & (thisstatementistrue == false)

Alex Pilk..

Re: Does this if statement work correctly?

4 months ago

I just want the loop to start over with different i if thisstatementistrue==true. That's why there are empty blocks.

But if EACH iteration thisstatementistrue==true, then the function must return true and if ANY iteration fails ( thisstatementistrue == false) function must return false. Right?

GoToLoop

Re: Does this if statement work correctly?

4 months ago

I thought you wanted to confirm the function's outcome, that is,

what passed values ( exeption) would make it return true or false.

But actually you want to fix it for something that is hard for us to guess,

since we got no idea what is that thisstatementistrue expression!

I just want the loop to start over with different i if thisstatementistrue==true.

Start over w/ a different value for iterator i?

Modifying the iterator for some arbitrary value in the middle of it can lead to infinite loop!

Where iterator i never reaches >= whatever.length!

But if EACH iteration thisstatementistrue==true, then the function must return true...

Isn't it enough for the loop to finish normally (when i >= whatever.length) to reach return true; at the bottom?

Why do you need to count how many times thisstementistrue became true???

And based on what? Since the innermost if () block only happens once when i == exeption anyways!

And of course, it's enough to thisstementistrue == false for the function to get a forced quit by return false;

GoToLoop

Re: Does this if statement work correctly?

4 months ago

Here's how I laid out your code to visualize it better:

boolean myFunction(int exeption) {
  for (int i = 0; i < whatever.length; i++) {
    if (i == exeption) {  }

    else
      if (thisstatementistrue) {  }
      else  return false;
  }

  return true;
}

PhiLho

Re: Does this if statement work correctly?

4 months ago

If I understand correctly the second message, you need a boolean to define the return value. If you return inside the loop, you won't finish it. See the answer of the https://forum.processing.org/topic/default-for-if-statements-within-for-loops question.
An empty if block is not useful, you can just invert the condition: if (cond) {} else { doStuff(); } is the same that if (!cond) { doSuff(); }
And perhaps you can use keywords like break or continue. Look them up in the Reference page.

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