MissingInteger Javascript solution 100%/100%

missinginteger.js

function solution(A) {
  var F = []; // Found list
  var I = 0, V = 0; // Counter, container
    
  while (I < A.length) { // Iterate through the array
    V = A[I]; // Store the value
    I++; // Increase counter
    if (F[V]) continue; // If the value exists, continue
    F[V] = true; // Store the value
  }
    
  I = 0;
    
  do { // Look for the first value that doesn't appear
    I++;
  } while (F[I]) // We do this by looping through the array until falsy
    
  return I; // Return the number of times we iterated 
}