STL - 容器 - Map(二)

把Map用作关联式数组

MapAdvanceTest.cpp

#include <map>

#include <string>

#include <iostream>

#include <iomanip>

#include "MapAdvanceTest.h"

#include "../../Core/ContainerUtil.h"

using namespace std;

void MapAdvanceTest::useAsAssociativeArray()

{

    // 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

    ContainerUtil<StringFloatMap>::printMapInDiv(stocks, "Stock", "Price", );

    // boom (all prices doubled)

    StringFloatMap::iterator pos;

    for (pos = stocks.begin(); pos != stocks.end(); ++pos) {

        pos->second *= ;

    }

    // print all elements

    ContainerUtil<StringFloatMap>::printMapInDiv(stocks, "Stock", "Price", );

    // rename key from "VW" to "Volkswagen"

    // - provided only by exchanging element

    stocks["Volkswagen"] = stocks["VW"];

    stocks.erase("VW");

    // print all elements

    ContainerUtil<StringFloatMap>::printMapInDiv(stocks, "Stock", "Price", );

}

void MapAdvanceTest::run()

{

    printStart("useAsAssociativeArray()");

    useAsAssociativeArray();

    printEnd("useAsAssociativeArray()");

}

运行结果:

---------------- useAsAssociativeArray(): Run Start ----------------
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: 739
Stock: BMW Price: 1668
Stock: Daimler Price: 1638
Stock: Siemens Price: 1684.4
Stock: VW Price: 827

Stock: BASF Price: 739
Stock: BMW Price: 1668
Stock: Daimler Price: 1638
Stock: Siemens Price: 1684.4
Stock: Volkswagen Price: 827

---------------- useAsAssociativeArray(): Run End ----------------