title: Javascript : increment loop index by onclick return function inside
body: <p>I am very new in javascript and I am lost with this usecase: I have a function :</p>
  
  <pre><code>function1 (trialNumber, next2Pictures){
  1- Display 2 pictures 
  
  // 2- When a user clicks on one of the pictures
  2-1 write you clicked on picture 1(or 2) 
  2-2 increment trialNumber
  2-3 choose new 2pictues
  2-4 Return [newTrialNumber, new2Pictures]
  
   }
  </code></pre>
  
  <p>I have function2 that calls function1 as far as trialNumber didn't exceed totalTrialsNumber. I have this implementation</p>
  
  <pre><code>function2() {
  // 1- instantiate trialNumber and  next2Pictures
   // 2- loop
  while(trialNumber &lt; totalTrialsNumber) {
  [trialNumber, next2Pictures]= function1 (trialNumber, next2Pictures)
  console.log("trialNumber incremented properly")
  }
  }
  </code></pre>
  
  <p>the problem is I don't know how to properly return values from function1 that can be used in the while loop of function2. I really need to increment the trialNumber only when a user clicks on a picture. I have checked some answers online but still can't figure it out. </p>