post  Getline with type int

epiqu1n (39)   Link to this post
Hi, I am trying to make a program that writes and reads data from a file, and I am trying to read a number from a file and store it in a variable of type int.

1
2
3
 
getline (data, temp);

content[y].miles = (int) temp;


Data is the name of the file I opened, and temp is a temporary variable of type string since getline() only accepts type string for a parameter. I tried type casting from string to int but that doesn't work either. Is there any way to get a number from a file and store it as an int?
Bazzy (4111)   Link to this post
you can use data >> content[y].miles
or getline and then convert the string in a integer http://www.cplusplus.com/forum/articles/9645/
Duoas (3497)   Link to this post
I tend to prefer using stringstreams too, especially in user input:
1
2
3
4
5
6
7
8
9
10
11
12
 
#include <sstream>
...

fstream f( ... );
...

string s;
getline( f, s );
istringstream iss( s );
if (!(ss >> content[y].miles)) fooey();

...
epiqu1n (39)   Link to this post
Ok thanks I'll get working on that in a bit. New problem though - we recently learned stuff with structures and such. But for some reason when I make a array of a structure, and try to edit a member of it in a .h file, it doesn't work. I know that's a bit confusing the way I said it, here:
1
2
3
4
5
 
struct.h: In member function ‘int structures::srch()’:
struct.h:120: error: no match for ‘operator=’ in ‘((structures*)this)->structures::results[((structures*)this)->structures::result].structures::cars::name = ((structures*)this)->structures::content[ref]’
/usr/include/c++/4.3/bits/basic_string.h:501: note: candidates are: std::basic_string<_CharT, _Traits, _Alloc>& std::basic_string<_CharT, _Traits, _Alloc>::operator=(const std::basic_string<_CharT, _Traits, _Alloc>&) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>]
/usr/include/c++/4.3/bits/basic_string.h:509: note:                 std::basic_string<_CharT, _Traits, _Alloc>& std::basic_string<_CharT, _Traits, _Alloc>::operator=(const _CharT*) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>]
/usr/include/c++/4.3/bits/basic_string.h:520: note:                 std::basic_string<_CharT, _Traits, _Alloc>& std::basic_string<_CharT, _Traits, _Alloc>::operator=(_CharT) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>]

is just one of the errors I get. Line 120 is:
results[result].name = content[ref+0];
That line is in a file called "struct.h." There are no other problems with the program as I have run it before this edit. All the variables you see are declared and perfectly valid.
Last edited on
epiqu1n (39)   Link to this post
Never mind I figured out what's wrong - content was also a struct but I wasn't referencing it properly. Forgot haha sorry.
belkdaddy (15)   Link to this post
Just drop the class.
epiqu1n (39)   Link to this post
Alright stringstream worked perfectly. Thanks guys.

This topic is archived - New replies not allowed.