How can I keep looping until my variable equals user input? JavaScript

Question

This nested for adds up until i and j are both 3 currently. How can I reset the variables once they've capped so I can continue the loop?

Or is that not the correct thought process?

for (i=1; i<=3; i=i+1)
  {
   for (j=1; j<=3; j=j+1)
     {
      ans=i + j;
      document.write(i + "+" + j + "=" + "<br />");
      var user_input = prompt("What is your answer?",0);
      while (user_input != ans) {
      if (ans == user_input)
        {
         document.write("Yes, the answer is " + ans + "<br />");
        }
      else
        {
         document.write("No, the answer is " + ans + "<br />");
        } 
      }
    }  
  }

I've tried a while loop, but it's consistently crashing. I'm just a bit iffy on the logic of the problem.

What I'm trying to do:

If the user answers correctly at any point, the loop ends. But I don't want the math to add above 6. Once it hits 6 I'd preferably like it to reset back to for both i and j.

Sorry, still trying to understand. So if user answers correctly 9 times, you want to restart the whole process? — vabii
– vabii, Commented May 10, 2017 at 19:47
No if the user answers correctly at any point, the loop ends. But I don't want the math to add above 6. Once it hits 6 I'd preferably like it to reset back to for both i and j. — J Ben
– J Ben, Commented May 10, 2017 at 19:51
it's crashing because inside your while loop no variables are changing. If the answer was wrong, then it's going berzerk doing nothing else than if/else/if/else a zillion times per second — yezzz
– yezzz, Commented May 10, 2017 at 20:04
What is the while loop for? What if user answers wrong, would they get stuck at same question or go to next iteration? — vabii
– vabii, Commented May 10, 2017 at 20:14
The while-loop starts to run the code if the condition is true and keeps looping as long as the condition is true, in this case, if user_input != ans. If user answers wrong they get stuck inside that loop and with an overheating computer.. nothing else! — yezzz
– yezzz, Commented May 10, 2017 at 20:20

vabii · Accepted Answer · 2017-05-10 20:43:52Z

1

I think you don't need the while loop. Assuming if user answer wrong, they get new question and if they answer right, the whole process stops, please try this

var finish = false;
for (i=1; i<=3; i=i+1)
  {
   for (j=1; j<=3; j=j+1)
     {
      ans=i + j;
      console.log(i + "+" + j + "=" + "<br />");
      var user_input = prompt("What is your answer?",0);
      if (ans == user_input)
        {
            finish = true;
            console.log("Yes, the answer is " + ans + "<br />");
          break;
        }
      else
        {
            console.log("No, the answer is " + ans + "<br />");
        }
    }  
    if(finish){break;}
    if(i==3 && j==4){i =0; j=0}
  }

edited May 10, 2017 at 20:43

answered May 10, 2017 at 20:18

vabii

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1 Comment

J Ben Over a year ago

This is almost exactly what I'm looking for, except it still cuts out once ans=6. How can I reset the variables once they've hit the 3 each? Reinitialize them somewhere else in the loop?

Peter LaBanca · Accepted Answer · 2017-05-10 20:00:31Z

0

I would use a recursive function to do this. Using the nested loops is just scary, harder to read, and easier to get into an infinite loop condition:

var ans = 6;
function getInput() {
    var user_input = prompt("What is your answer?",0);
    if (ans == user_input) {
        document.write("Yes, the answer is " + ans + "<br />");
    }
    else {
        getInput();
    } 
}

getInput();

If you wanted the ans to change every time you go through the loop, you could add random number logic to set the answer:

var ans = Math.floor(Math.random() * 6) + 1;

answered May 10, 2017 at 20:00

Peter LaBanca

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