programming-for-dummies

150
Storing Data in a Variable
Table 2-1
Data Type
Byte
Boolean
Character
Integer
Single
Long
Double
String
Typical Storage Requirements for Different Data Types
Storage Size
1 byte
2 bytes
2 bytes
4 bytes
4 bytes
8 bytes
8 bytes
10 bytes + (2 * string length)
(If you had a string consisting of three letters, that string would take up 10
bytes of storage space plus (2 multiplied by three letters or 10 + (2 * 3),
which is 16 bytes.)
So when declaring variables as specific data types, you want to choose the
data type that can
✦ Hold a range of valid values.
✦ Uses the least amount of space as possible.
Storing Data in a Variable
After you declare a variable, store data in that variable as the following C
program demonstrates:
int age;
age = 15;
Line 1: Declares the age variable as an integer data type.
Line 2: Stuffs the number 15 into the age variable.
You can assign a fixed value (like 15) to a variable or any equation that creates
a value, such as
taxes_owed = salary * 0.30;
If the value of the salary variable is 1000, this command multiplies 1000
(the salary variable’s value) by 0.30, which is 300. The number 300 then
gets stored in the taxes_owed variable.