伙计们，我编写了以下代码用于在 C++ 中实现电话簿我正在做的是首先从三个包含姓名、地址和电话号码的文件中获取输入（你可能不会看整个代码），只看底部
现在我让用户在运行时添加要添加的联系人，这些值存储在一个类中。现在我删除包含姓名、地址和号码的文件，并使用 ofstream 将新数据写入其中，当用户再次运行“电话簿”时将检索这些数据
但是，在程序运行一次后我看不到文件中的任何输入，并且我在运行时添加了一些值。有人能帮我吗？提前致谢
#include<iostream>//Include Header Files
#include<cstdlib>
#include<fstream>
#include<string>
using namespace std;
class contact{
public:
string name;//ALL CLASS VARIABLES ARE PUBLIC
int phonenumber;
string address;
contact(){//Constructor
name= "Noname";
phonenumber= 0;
address= "Noaddress";
}
};
int main(){
contact *d;
d= new contact[200];
string name,add;
int choice,modchoice,k=0;//Variable for switch statement
int phno,phno1;
int i=0;
int initsize=0, i1=0;//i is declared as a static int variable
bool flag=false,flag_no_blank=false;
//TAKE DATA FROM FILES.....
//We create 3 files names, phone numbers, Address and then abstract the data from these files first!
fstream f1;
fstream f2;
fstream f3;
string file_input_name;
string file_input_address;
int file_input_number;
f1.open("./names");
while(f1>>file_input_name){
d[i].name=file_input_name;
i++;
}
initsize=i;
f2.open("./numbers");
while(f2>>file_input_number){
d[i1].phonenumber=file_input_number;
i1++;
}
i1=0;
f3.open("./address");
while(f3>>file_input_address){
d[i1].address=file_input_address;
i1++;
}
cout<<"\tWelcome to the phone Directory\n";//Welcome Message
do{
//do-While Loop Starts
cout<<"Select :\n1.Add New Contact\n2.Update Existing Contact\n3.Display All Contacts\n4.Search for a Contact\n5.Delete a Contact\n6.Exit PhoneBook\n\n\n";//Display all options
cin>>choice;//Input Choice from user
switch(choice){//Switch Loop Starts
case 1:{
i++;//increment i so that values are now taken from the program and stored as different variables
i1++;
do{
cout<<"\nEnter The Name\n";
cin>>name;
if(name==" "){cout<<"Blank Entries are not allowed";
flag_no_blank=true;
}
}while(flag_no_blank==true);
flag_no_blank=false;
d[i].name=name;
cout<<"\nEnter the Phone Number\n";
cin>>phno;
d[i1].phonenumber=phno;
cout<<"\nEnter the address\n";
cin>>add;
d[i1].address=add;
i1++;
i++;
break;//Exit Case 1 to the main menu
}
case 2: {
cout<<"\nEnter the name\n";//Here it is assumed that no two contacts can have same contact number or address but may have the same name.
cin>>name;
int k=0,val;
cout<<"\n\nSearching.........\n\n";
for(int j=0;j<=i;j++){
if(d[j].name==name){
k++;
cout<<k<<".\t"<<d[j].name<<"\t"<<d[j].phonenumber<<"\t"<<d[j].address<<"\n\n";
val=j;
}
}
char ch;
cout<<"\nTotal of "<<k<<" Entries were found....Do you wish to edit?\n";
string staticname;
staticname=d[val].name;
cin>>ch;
if(ch=='y'|| ch=='Y'){
cout<<"Which entry do you wish to modify ?(enter the old telephone number)\n";
cin>>phno;
for(int j=0;j<=i;j++){
if(d[j].phonenumber==phno && staticname==d[j].name){
cout<<"Do you wish to change the name?\n";
cin>>ch;
if(ch=='y'||ch=='Y'){
cout<<"Enter new name\n";
cin>>name;
d[j].name=name;
}
cout<<"Do you wish to change the number?\n";
cin>>ch;
if(ch=='y'||ch=='Y'){
cout<<"Enter the new number\n";
cin>>phno1;
d[j].phonenumber=phno1;
}
cout<<"Do you wish to change the address?\n";
cin>>ch;
if(ch=='y'||ch=='Y'){
cout<<"Enter the new address\n";
cin>>add;
d[j].address=add;
}
}
}
}
break;
}
case 3 : {
cout<<"\n\tContents of PhoneBook:\n\n\tNames\tNumbers\tAddresses\n";
for(int t=0;t<=i;t++){
if(d[t].name=="Noname") continue;
cout<<".\t"<<d[t].name<<"\t"<<d[t].phonenumber<<"\t"<<d[t].address<<"\n";
}
cout<<"\n\n\n\n";
break;
}
case 4:{
cout<<"Enter a name to search\n";
cin>>name;
cout<<"\n\nSearching.........\n\n";
for(int j=0;j<=i;j++){
if(d[j].name==name){
k++;
cout<<k<<".\t"<<d[j].name<<"\t"<<d[j].phonenumber<<"\t"<<d[j].address<<"\n\n";
int val=j;
}
}
cout<<"\nA total of "<<k<<" contact names were found having the name"<<name;
break;
}
case 6:{
cout<<"\n\nClosing the phonebook...Visit Again\n";
flag=true;
break;
}
case 5: {
cout<<"\nEnter the contact-name\n";//Here it is assumed that no two contacts can have same contact number or address but may have the same name.
cin>>name;
int k=0,val;
cout<<"\n\nSearching.........\n\n";
for(int j=0;j<=i;j++){
if(d[j].name==name){
k++;
cout<<k<<".\t"<<d[j].name<<"\t"<<d[j].phonenumber<<"\t"<<d[j].address<<"\n\n";
val=j;
}
}
char ch;
cout<<"\nTotal of "<<k<<" Entries were found....Do you wish to delete?\n";
if(k==0) break;
string staticname;
staticname=d[val].name;
cin>>ch;
if(ch=='y'|| ch=='Y'){
cout<<"Which entry do you wish to delete ?(enter the old telephone number)\n";
cin>>phno;
for(int j=0;j<=i;j++){
if(d[j].phonenumber==phno && staticname==d[j].name){
val=j;
}
}
for(int j=val;j<=i-1;j++){
d[j].name=d[j+1].name;
d[j].phonenumber=d[j+1].phonenumber;
d[j].address=d[j+1].address;
}
d[i].name="Noname";
d[i].phonenumber=0;
d[i].address="Noaddress";
}
break;
}
}
}
while(flag==false);
std::ofstream f4("./names");
f4.close();
std::ofstream f5("./numbers");
f5.close();
std::ofstream f6("./address");
f6.close();
f1.close();
f2.close();
f3.close();
ofstream f7,f8,f9;
f7.open("names");
f8.open("numbers");
f9.open("address");
int y=0;
string w;
w=d[0].name;
while(f7<<w && y<=i){
if(w=="Noname") y++; continue;
y++;
w=d[y].name;
}
y=0;
int v;
v=d[0].phonenumber;
while(f8<<v && y<=i){
if(v==0){y++; continue;}
y++;
v=d[y].phonenumber;
}
y=0;
string u;
u=d[0].address;
while(f9<<u && y<=i ){
if(u=="Noaddress"){
continue;
y++;
}
y++;
u=d[y].address;
}
return 0;
}