[DNA Pairing] Help me understand my code

1

I’ve already solved this algorithm challenge, so please look away if you don’t want to spoil it for yourself.

I don’t understand the behavior of the code below. It’s what I had right before I fixed it.

function pairElement(str) {
  var DNAWrapper = [];
  var pairWrapper = [];
  var arr = str.split('');
  
  function pushIntoArrs(pairVal) {
    pairWrapper.push(arr[i], pairVal);
    DNAWrapper.push(pairWrapper);
    //pairWrapper = []; uncomment this to pass problem
  }
  
  for (var i = 0; i < arr.length; i++) {
    if (arr[i] == 'G') {
      pushIntoArrs('C');
    }
    else if (arr[i] == 'C') {
      pushIntoArrs('G');
    }
    else if (arr[i] == 'A') {
      pushIntoArrs('T');
    }
    else {
      pushIntoArrs('A');
    }
  } // close for

  return DNAWrapper;
}

pairElement("GCG");

This returns [["G","C","C","G","G","C"],["G","C","C","G","G","C"],["G","C","C","G","G","C"]]

But, I expected it to return [["G","C"],["G","C","C","G"],["G","C","C","G","G","C"]] due to the for loop. I know this wouldn’t solve the challenge, but I want to understand what’s happening. Thanks for any help!

2

It is how you are pushing in. With your looping logic. Mostly the looping logic.

Foreach