в 14:21, 25 мая 2010

2010-05-25T14:21:06Z

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2010-05-25T10:25:53Z

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==Update a key value==

<source lang="cpp">

/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/
#include <iostream>
#include <map>
#include <string>
using namespace std;
int main()
{
/* create map / associative array
* - keys are strings
* - values are floats
*/
typedef map<string,float> StringFloatMap;
StringFloatMap stocks; // create empty container
// insert some elements
stocks["BASF"] = 369.50;
stocks["VW"] = 413.50;
stocks["Daimler"] = 819.00;
stocks["BMW"] = 834.00;
stocks["Siemens"] = 842.20;
// print all elements
StringFloatMap::iterator pos;
for (pos = stocks.begin(); pos != stocks.end(); ++pos) {
cout << "stock: " << pos->first << "\t"
<< "price: " << pos->second << endl;
}
cout << endl;

/* rename key from "VW" to "Volkswagen"
* - only provided by exchanging element
*/
stocks["Volkswagen"] = stocks["VW"];

// print all elements
for (pos = stocks.begin(); pos != stocks.end(); ++pos) {
cout << "stock: " << pos->first << "\t"
<< "price: " << pos->second << endl;
}
cout << endl;
}
/*
stock: BASF price: 369.5
stock: BMW price: 834
stock: Daimler price: 819
stock: Siemens price: 842.2
stock: VW price: 413.5
stock: BASF price: 369.5
stock: BMW price: 834
stock: Daimler price: 819
stock: Siemens price: 842.2
stock: VW price: 413.5
stock: Volkswagen price: 413.5

*/

</source>

==Use push_back to add object to vector==

<source lang="cpp">
#include <algorithm>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <string>
#include <utility>
#include <vector>
using namespace std;
class PC{
public:
enum PC_type { Dell, HP, IBM, Compaq };
PC( PC_type appliance = Dell, int model = 220,int serial = 0 );
bool operator<( const PC& rhs ) const;
PC_type appliance() const;
int model() const;
string name() const;
void print() const;
int serial() const;
private:
PC_type appliance_;
int model_;
int serial_;
};
inline
PC::PC( PC::PC_type appliance, int model,
int serial )
: appliance_( appliance ), model_( model ), serial_( serial )
{}
inline
bool PC::operator<( const PC& rhs ) const
{ return appliance() < rhs.appliance() ||
( appliance() == rhs.appliance() && model() < rhs.model() );
}
inline
PC::PC_type PC::appliance() const
{ return appliance_; }
inline
int PC::model() const
{ return model_; }
string PC::name() const
{
string what;
switch( appliance() )
{
case Dell: what = "Dell"; break;
case HP: what = "HP"; break;
case IBM: what = "IBM"; break;
case Compaq: what = "Compaq"; break;
default: what = "Unknown appliance"; break;
}
return what;
}
inline
void PC::print() const
{
char oldfill = cout.fill();
cout << name() << " - Model "
<< model() << ", Serial number "
<< serial() << endl;
}
inline
int PC::serial() const
{ return serial_; }
bool greater_model( const pair<PC::PC_type,PC> p,int min_model );
int main( )
{
const PC::PC_type kind[] = { PC::IBM,PC::Dell,PC::HP };
vector<PC> v;
for( int i = 0; i < 3; ++i )
v.push_back( PC( kind[i], i, i ) );

}

</source>

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в 14:21, 25 мая 2010

Admin: 1 версия: Импорт контента...