Thinking about Strings
Intro to Computer Science
CS1510, Section 2
Dr. Sarah Diesburg
What are strings?
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Sequences of characters
We will often work with sequences of data
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String is just a specific example
We will see many of the things we do with
strings later on with other sequences of data
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Sequences of data
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Can work with size of sequence
Can work with individual pieces of information
in the sequence
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Thought Exercise
Suppose I give you a string
>>> mesg = “Today is Friday”
 What is the length of that string?
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Thought Exercise
>>> mesg = “Today is Friday”
 mesg[1]
 mesg[11]
 mesg[-1]
 mesg[3:9]
 mesg[10:]
 mesg[10:37]
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Note about Answers
>>> msg[3:9]
 Answer is
ay is
 But how do we write this to show spaces?
 On answer sheets or tests, be very careful
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If I can’t tell that there are spaces, I might take
points off
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Questions so far?
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Let’s talk about the lab
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Sequences, indexes, and slicing.
Reversing the Str
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Working backwards and appending
Working forwards and prepending
Counting the vowels
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Handling both cases
Using methods and handling only one case