programming-for-dummies

Using Comparison Operators 173
Comparing two numbers is straightforward, such as
5 > 2
Comparing two numbers always calculates the same result. In this case, 5 > 2
always returns a True value. What gives comparison operators more flexibility
is when they compare variables, such as
Age > 2
Depending on what the value of the Age variable may be, the value of this
comparison can be either True or False.
Comparing numbers may be straightforward, but comparing strings can be
more confusing. Remember, computers only understand numbers, so they
use numbers to represent characters, such as symbols and letters.
Computers use the number 65 to represent A, the number 66 to represent B,
all the way to the number 90 to represent Z. To represent lowercase letters,
computers use the number 97 to represent a, 98 to represent b, all the way
up to 122 to represent z.
Book II
Chapter 3
Manipulating Data
The specific numbers used to represent every character on the keyboard can
be found on the ASCII table, which you can view at www.asciitable.com.
That’s why in Table 3-7 the comparison between A > a is False because the
computer replaces each character with its equivalent code. So the comparison
of characters
“A” > “a”
actually looks like this to the computer:
65 > 97
The number 65 isn’t greater than 97, so this comparison returns a False
value.
Comparing a string of characters works the same way as comparing single
characters. The computer examines each string, character by character, and
translates them into their numeric equivalent. So if you had the comparison
“aA” > “aa”
The computer converts all the characters into their equivalent values,
such as
97 65 > 97 97