这个c£«£«程序中char city[20]; 的作用是什么 ?

#include <fstream>

#include <iostream>

using namespace std;

int main()

{

    fstream inout;

inout.open("city.txt",ios::out);

inout<<"Dallas"<<" "<<"tonghua"<<" "<<"长春"<<" " ;

inout.close();

inout.open("city.txt",ios::app | ios::out);

inout<<"罗马"<<" "<<"巴黎"<<" ";

inout.close();

char city[20];

inout.open("city.txt",ios::in);

while(!inout.eof())

{inout>>city;

cout<<city<<" ";

                 } 

                 inout.close();

                 

    system("PAUSE");

    return 0;

}