title: Compare elements in each position of an array
body: <p>I have two arrays </p>
  
  <pre><code>a = [ab,bc,cd]
  b = [bc,ab,cd]
  </code></pre>
  
  <p>I want to compare each element of a with each element of b and then increase <code>counter += 1</code> if they match, else <code>counter -1</code> and display <code>counter</code> </p>
  
  <pre><code>counter=0
  for i in a:
   for j in b: 
     if a[i-1] == b[j-1]:
        counter = counter + 1
     elif a[i-1] != b[j-1]:
        counter = counter - 1
    print counter
  </code></pre>
  
  <p>I am getting weird results, I am new to programming and help is appreciated.</p>
  
  <p>Sorry for copy paste error</p>