Variable Declarations

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!! Identifiers

As in all programming languages, we use identifiers to name things such as variables, functions, data types, classes, etc. Identifiers in C++:

• can consist of characters, digits, and the underscore
• must begin with a character
• are case sensitive
• can be of any length, though the first 32 characters must be unique.

Variables

Variables in C++ must be explicitly declared as they are in Java.

(:source lang=cpp:)

int grade,
    sum,
    total;

double average,
       salary;

In C++, variables are not initialized when they are created. You can declare a variable and initialize it at the same time

(:source lang=cpp:)

int total = 0;
double taxRate = 0.05;

Data Types

C++ provides a number of primitive data types including

Integers
char	1-byte signed
short	2-bytes signed
int	size of system word (4-bytes: 32-bit architecture) (8-bytes: 64-bit architecture)
long	4-bytes signed
long long	8-bytes signed (implemented in software)
unsigned char	1-byte unsigned
unsigned short	1-byte unsigned
unsigned short	2-bytes unsigned
unsigned int	same size as an int
unsigned int	4-bytes unsigned
unsigned long long	8-bytes unsigned (implemented in software)
Reals
float	4-bytes
double	8-bytes
long double	12-bytes
Other
bool	4-bytes
enum	8-bytes
reference	same size as an int

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