title: Recursively swap pairs of letters in a string in java
body: <p>For example, if I call exchangePairs("abcdefg"), I should receive "badcfeg" in return.</p>
  
  <p>This is for a homework assignment, any kind of pseudocode would be very helpful. I am just beginning to learn recursion and up until this problem I haven't had too much of an issue. </p>