programming-for-dummies

528
Using Operators
Table 1-2
Typical Floating Point Data Types
Data Type Number of Bytes Range
Float 4 –1.4023 E–45 to 3.4028 E38
Double 8 –4.9406 E– 324 to 1.7977 E308
Long double 8 or 12 –4.9406 E– 324 to 1.7977 E308
Real numbers (float, double, and long double) are always signed data types
(positive or negative). With many compilers, the range of values is identical
between double and long double data types.
Declaring Boolean values
In the C language, there are no Boolean data types. Any nonzero value
is considered to represent True, and zero represents False. To mimic a
Boolean data type, many C programmers define numeric values for True
and False, such as
#define FALSE 0
#define TRUE 1
int flag = FALSE;
Although this is workable, such an approach forces you to create an integer
variable to represent a Boolean value. To avoid this problem, C++ offers a
special Boolean data type (like most programming languages), such as
bool variablename;
A C++ Boolean data type can hold a value of 0 (False) or 1 (True).
Using Operators
The three types of operators used are mathematical, relational, and logical.
Mathematical operators calculate numeric results such as adding, multiplying,
or dividing numbers, as shown in Table 1-3.
Table 1-3
Mathematical Operators
Mathematical Operator Purpose Example
+ Addition 5 + 3.4
- Subtraction 203.9 – 9.12
* Multiplication 39 * 146.7
/ Division 45/ 8.41
% Modula division (returns the remainder) 35 % 9 = 8