# Going Deeper with Strings

## 2. Len

`len`

is a built-in function that returns the number of characters in a string:

>>> fruit = 'banana' >>> len(fruit) 6To get the last letter of a string, you might be tempted to try something like this:

>>> length = len(fruit) >>> last = fruit[length] IndexError: string index out of rangeThe reason for the

`IndexError`

is that there is no letter in ’`banana`

’ with the index 6. Since we started counting at zero, the six letters are numbered 0 to 5. To get the last character,
you have to subtract 1 from `length`

:
>>> last = fruit[length-1] >>> last 'a'Or you can use negative indices, which count backward from the end of the string. The expression

`fruit[-1]`

yields the last letter, `fruit[-2]`

yields the second to last, and so on.