Global class variable
#include<iostream.h>
class test
{
int i;
public:
test()
{
i=25;
for(int ctr=0; ctr<10;ctr++)
{
cout<<"Counting at"<<ctr<<"\n";
}
}
~test(){};
};
test anObject;
main()
{
return 0;
}Counting at0
Counting at1
Counting at2
Counting at3
Counting at4
Counting at5
Counting at6
Counting at7
Counting at8
Counting at9
Global variables are known throughout the entire program and may be used by any piece of code.
#include <stdio.h>
void func1(void), func2(void);
int count;
main(void)
{
count = 100;
func1();
return 0;
}
void func1(void)
{
int temp;
temp = count;
func2();
printf("count is %d", count); /* will print 100 */
}
void func2(void)
{
int count;
for(count=1; count<10; count++)
putchar(".");
}Use a global variable
#include <iostream>
using namespace std;
void func1();
void func2();
int count; // This is a global variable.
int main()
{
int i; // This is a local variable
for(i=0; i<10; i++) {
::count = i * 2;
func1();
}
return 0;
}
void func1()
{
cout << "count: " << ::count; // access global count
cout << "\n";
func2();
}
void func2()
{
int count;
for(count=0; count<3; count++)
cout << ".";
}count: 0
...count: 2
...count: 4
...count: 6
...count: 8
...count: 10
...count: 12
...count: 14
...count: 16
...count: 18
...
Use :: to reference global variable
#include <iostream>
using namespace std;
int global_name = 1001;
int main(void){
int global_name = 1; // Local variable
cout << "Local variable value " << global_name << "\n";
cout << "Global variable value " << ::global_name << "\n";
}
