title: string addition I coderbyte completely stumped
body: <p>Can anyone explain the solution to me like a 6 year old? I haven't been able to make sense of the solutions. Maybe some code comments?</p>
  
  <p>Thank you.</p>
  
  <hr>
  
  <p>I've spent the last 2 hours on coderbyte trying to solve this one. Here's the question:</p>
  
  <blockquote>
    <p>Have the function ArrayAdditionI(arr) take the array of numbers stored
    in arr and return the string true if any combination of numbers in the
    array can be added up to equal the largest number in the array,
    otherwise return the string false. For example: if arr contains [4, 6,
    23, 10, 1, 3] the output should return true because 4 + 6 + 10 + 3 =
    23. The array will not be empty, will not contain all the same elements, and may contain negative numbers.</p>
  </blockquote>
  
  <p>I've scoured the internet, read through a bunch of people's solutions from the people's answers on coderbyte itself, but without any comments I'm really struggling to figure out how this is done. I've started over countless times, so I'm not even sure if this last attempt is any better or not. </p>
  
  <p>I understand that I'll need to loop through somehow and test every combination index 5, index 4, index 3, index 2, index 1, AND every combination of less than all of those (ie just index 5 and index 3). I just can't figure out how to do that. If I knew the list would always be an array of 5 numbers, and it required all 5, I would write 5 loops all equally nested inside of one big one, right? However, with the added complexity of not requiring all numbers and not knowing the length of the array for all cases, I am completely stumped. I tried using Math.floor(Math.random() * array.length); to generate a list of numbers... but that didnt work either. </p>
  
  <pre><code>function ArrayAdditionI(arr) { 
    var longest = arr.sort( function(a,b) { return a-b });
    var longest = longest[longest.length - 1];
  
    var sumArr = function (arrb) {
      var sum = 0;
      for (var z = 0; z &lt; arrb.length; z++){
        sum += arrb[z];
      }
      return sum;
    };
  
    for (var i = 0; i &gt; arr.length; i++) {
      for (var y = 0; y &gt; arr.length; i++) {
      testArr.push(arr[i]);
      if (sumArr(testArr) === longest) {
        return true;
      }
      testArr.push(... its 4am and I'm stumped!...)
      }}
  
  
    // code goes here  
    return false; 
  
  }
  
  // keep this function call here 
  // to see how to enter arguments in JavaScript scroll down
  ArrayAdditionI(readline());           
  </code></pre>