1. CEV208 Computer Programming
Strings
Spring 2013

2. A string is a sequence A string is a sequence of characters. index
(its value has to be an integer)
index
(its value has to be an integer)
Careful!:

3. len
len is a built-in function that returns the number of characters in a string.

4. Traversal Traversal: Processing a string one character at a time.
A traversal with a while loop:
A traversal with a for loop:

5. Assignment

6. Traversal
What is the output of this program?

7. String slices
slice: a segment of a string

8. String slices

9. Strings are immutable
object : Assume that it is the same thing as a value for now.
item : One of the values in a sequence.

10. Searching
Search: Traversing a sequence and returning when we find what we are looking for.

11. Counter
ASSIGNMENT:

12. string methods
method: similar to a function, but the syntax is different.
invocation: a call to a method.
method upper takes a string and returns a new string with all uppercase letters:
method find:
method count:

13. The in operator
What does this function do?

14. String comparison The relational operators work on strings.
You may use the other relational operators for putting words in alphabetical order:
CAREFUL!: In Python, all the uppercase letters come before all the lowercase letters.

15. Debugging
This function contains two errors:

16. Debugging

17. Glossary object immutable sequence traverse item search index counter
slice
method
empty string
invocation