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Rucker
n00b
Joined: 30 Oct 2002
Posts: 25
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 Posted: Tue Jan 28, 2003 5:26 pm Post subject: Can someone explain to me these issues I have with iostream? |
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I am doing a problem for an assignment in school that uses two structs:
| Code: |
struct Address
{
char city[15];
char state[3];
};
struct EmployeeInfo
{
char name[20];
int age;
float payrate;
Address address;
};
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I also have a function that inputs data into an array of three EmployeInfos:
| Code: |
void Initialize(EmployeeInfo Employees[])
{
for(int x = 0; x < 3; x++)
{
cout << "Enter name for employee " << x + 1 << ": ";
cin.getline(Employees[x].name, 20);
cout << "Enter age for employee " << x + 1 << ": ";
cin >> Employees[x].age;
cout << "Enter payrate for employee " << x + 1 << ": ";
cin >> Employees[x].payrate;
cin.ignore();
cout << "Enter city for employee " << x + 1 << ": ";
cin.getline(Employees[x].address.city, 15);
cout << "Enter state for employee " << x + 1 << ": ";
cin.getline(Employees[x].address.state, 3);
}
}
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When I include iostream this way:
#include <iostream>
using namespace std;
then everything works as expected.
If instead I simply do #include <iostream.h> then I get this:
| Quote: | Enter name for employee 1: Mike Rucker
Enter age for employee 1: 20
Enter payrate for employee 1: 10
Enter city for employee 1: Cottage Grove
Enter state for employee 1: MN
Enter name for employee 2: Enter age for employee 2:
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To get it to work correctly I have to put a cin.ignore(); statement as the last line of the for loop.
Can someone explain to me what causes this difference in behavior? |
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ryan83vt
Guru
Joined: 28 Oct 2002
Posts: 370
Location: Blacksburg, VA
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| Posted: Tue Jan 28, 2003 11:00 pm Post subject: |
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all the .h headers are no longer in the standard.
what used to be #include<iostream.h> is now #include<iostream> and the code is put in a namespace (namely, std).
A namespace makes it so that you only get the code you want. It groups code together into a unit. Before, if you said #include<iostream.h> you get the code for the WHOLE include file. Now, you can just say
| Code: |
#include<iostream>
using std::cin;
using std::cout;
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Alternatively,
| Code: |
#include<iostream>
.....
.....
//somewhere in your program
std::cin>>a_variable;
std::cout<<"hello world";
//this way, however, you must prefix everything from iostream inside the namespace with std::
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and you will only get the code for cin and cout. You can also do what you were doing and use
| Code: |
using namespace std;
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and this will include all the code in the namespace called std.
I hope this answers your question. Basically, don't use iostream.h or any other .h header. Many of the old c-style headers (ie math.h) have been converted also -- so look for those by using #include<cmath> (c + the old name)
Happy coding! |
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BigRedDot
n00b
Joined: 29 Oct 2002
Posts: 67
Location: Austin
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| Posted: Tue Jan 28, 2003 11:10 pm Post subject: |
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| Quote: | all the .h headers are no longer in the standard.
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This implies that they were ever in the standard to begin with; they were not.
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Even if you are one-in-a-million, there are still 6000 people just like you. |
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