Aside from sequences of numbers, we can also loop over Strings! After all, a string is a collection of characters.

Let’s say we wanted to look over a string and see if it contains "z". In a program, that means we would loop through the characters of a String. In each iteration would we check if the character was a "z".

var quote = "our whole life is solving puzzles."

for character in quote {
  print(character)
  if character == "z" {
    print("There's a z!")
  }
}

The basic structure of the for-in loop remains the same, but now we’re going through each character of our String, instead of each number of a range.

The example above would print out:

o
u
r

w
h
...
z
There's a z!
z
There's a z!
l
e
s 
.

In our print out, we see that each character of the String is printed out (we skipped over a few characters with a ... to lessen the amount printed). Additionally, each time character is a "z" we also print out There's a z!.