C++ LANGUAGE VARIABLE DEFINITION PAGE 16

COMPUTER LANGUAGES HTML,C,C++.JAVA,.NET AND MULTIMEDIA basics and programs click home button

C++ LANGUAGE VARIABLE DEFINITION

Variable Definition in C++ 


A variable definition tells the compiler where and how 
much storage to create for the variable. A variable definition 
specifies a data type, and contains a list of one or more 
variables of that type as follows: 

type variable_list; 

Here, type must be a valid C++ data type including char, 
w_char, int, float, double, bool or any user-defined object, 
etc., and variable_list may consist of one or more identifier 
names separated by commas. Some valid declarations are shown here: 

int    i, j, k; 

char   c, ch; 

float  f, salary; 

double d; 

The line int i, j, k; both declares and defines the variables 
i, j and k; which instructs the compiler to create variables 
named i, j and k of type int. 

Variables can be initialized (assigned an initial value) 
in their declaration. The initializer consists of an equal 
sign followed by a constant expression as follows: 

type variable_name = value; 

Some examples are: 

extern int d = 3, f = 5;    // declaration of d and f. 
 
int d = 3, f = 5;           // definition and initializing d and f.  

byte z = 22;                // definition and initializes z. 
 
char x = 'x';               // the variable x has the value 'x'. 

For definition without an initializer: variables with static 
storage duration are implicitly initialized with NULL (all bytes 
have the value 0); the initial value of all other variables is undefined.