The syntax used to declare a variable is "type
Eg: char letter;
float the_float;
int a, b, c, d;
A variable in C++ must be declared (the type of variable) and defined (values assigned to a variable) before it can be used in a program. In C++, all language keywords, all functions and all variables are case sensitive. So word ball and Ball are different keywords.
Scope of variables:
The scope of a variable can be classified in to two categories naming global and local variables.
Local variables - Local variables can be only accessed within the code itself and not outside of the function. So the scope of a local variable is limited to the function in which the variables are declared.
Global variables – Global variables can be used within and outside of any function in the program. To cater this requirement the variables are declaring outside of a function block.
For Eg:
#include
using namespace std;
int iValue1 = 1; // Global variable
int iValue2 = 2; // Global variable
int main()
{
char zCh('B'); // Local variable
cout << "Value of global variable iValue1:" << iValue1 << endl;
cout << "Value of global variable iValue2:" << iValue2 << endl;
cout << "Character in local variable zCh: " << zCh << endl;
int sum, number = 3; // Local variables with and without initialization
sum = number + 5;
cout << "Value of sum: " << sum << endl;
getchar();
return 0;
}
