R. Necaise | CppPrimer / Variable Declarations

Identifiers

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

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

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

int total = 0;

double taxRate = 0.05;

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`