The best thing about arrays is that you can loop over them in the same way you can loop over individual letters in a string. In fact the code for both loops is pretty much identical! The code below is a updated version of the friends code we saw a few exercises ago.

friends = ["bert", "sally", "sue", "martin"]
x = 0
while x < len(friends) -1:
    print friends[x], "is friends with", friends[x+1]
    x = x + 1

The loop needs to end before it reaches the last value as there is no one left for Martin to be friends with (poor Martin!). The above code combines arrays, loops and expressions together in order to reduce the amount of code needed to do the same task.

Try the above code and then add "percy" to the array (at the end after martin). You should not need to change any of the code other than line 1 to get it working!