Missing integer in JS

The missing integer problem asks for the return of the smallest positive integer (greater than 0) that does not occur in the given array. For example, given A = [1, 3, 6, 4, 1, 2], the function should return 5. Given A = [1, 2, 3], the function should return 4. Given A = [−1, −3], the function should return 1.

To start we set a variable for our smallest number.

let min = 1

We set the minimum to 1 because the problem stats greater than 0. Next, we can sort our array from lowest to highest.

A.sort(function(a,b){a - b});

Once we have a sorted array we loop through the array and check each number if they are positive and are equal to our current minimum number.

for (let i in A) {             
  if (A[i] > -1 && A[i] == min) {                     
   min++;             
  }         
}

After we finish looping through we return our min.

return min;