programming-for-dummies

178
Converting Data Types
If the value of the Age variable is 1, this is how the Xor operator evaluates
an answer:
(Age > 2) XOR (Age >= 18)
(1 > 2) XOR (1 >= 18)
False XOR False
False
The Xor operator returns a False value if both values are False or if both
values are True.
Rather than use the word xor to represent the Xor operator, curly bracket
languages, such as C/C++, use the caret (^) symbol instead.
Boolean operators are used most often to make decisions in a program, such
as a video game asking, “Do you want to play again?” When you choose
either Yes or No, the program uses a comparison operator, such as
Answer = “Yes”
The result depends on your answer:
✦ If your answer is Yes, the preceding comparison operation returns a
True value.
If this comparison operation is True, the video game plays again.
✦ If your answer is No, the preceding comparison operation returns a
False value.
✦ If this comparison operation is False, the video game doesn’t play
again.
Converting Data Types
Programming languages are often divided into two categories, depending on
their variables:
✦ A type-safe language forces you to declare your variables, and their data
types, before you can use them.
See Chapter 2 in this mini-book for more information about declaring
variables types.
✦ A typeless language lets you store any type of data in a variable.
One moment a variable can hold a string, another moment it can hold an
integer, and then another moment it might hold a decimal number.