CODEWITHSUNDEEP
c++dictionarymfcstdmap
Astro - Amit
Astro - Amit

Reputation: 767

Container with char* key and int value

I need a container in which i can store a char* key and int value.

I can use std::map and mfc CMap but i dont know few operation when using char* as key.

Something like below:

#include"iostream"
#include<map>
using namespace std;

std::map<char*,int>Mymap;
or
//Cmap<char*, char*, int, int>Mymap;

char* p = "AAA";
char* q = "BBB";

int p_val = 10;
int q_val = 20;

int main()
{
    // How to use insert, find and access keys      

    return 0;
}

I want to know both the solutions with map as well as CMap.

Upvotes: 2

Views: 2632

Answers (2)

Astro - Amit
Astro - Amit

Reputation: 767

Here is the Example how to use std""map with char* key and int value.

//Example of std::map with char* key and int as value.

#include"iostream"
using namespace std;
#include<map>

struct cmp_str
{
    bool operator()(char *first, char  *second)
    {
        return strcmp(first, second) < 0;
    }
};

typedef std::map<char*,int, cmp_str>MAP;
MAP myMap;

void Search(char *Key)
{
    MAP::iterator iter = myMap.find(Key);

    if (iter != myMap.end())
    {
        cout<<"Key : "<<(*iter).first<<" found whith value : "<<(*iter).second<<endl;
    }
    else
    {
        cout<<"Key does not found"<<endl;
    }
}

int main()
{
    char *Key1 = "DEV";
    char *Key2 = "TEST";
    char *Key3 = "dev";

    //Insert Key in Map
    myMap.insert(MAP::value_type(Key1, 100));
    myMap.insert(MAP::value_type(Key2, 200));


    // Find Key in Map
    Search(Key1);       // Present in Map
    Search(Key2);       // Present in Map

    Search(Key3);       // Not in Map as it's case sensitive

    myMap.erase(Key2);  // Delete Key2
    Search(Key2);       // Not in Map as deleted 

    return 0;
}

By Using MFC cmap also we can achieve the same but the operations might(functions) change.

Upvotes: 2

darxsys
darxsys

Reputation: 1570

Be aware that if you don't write your own comparator, stuff that will actually be compared by internal map functions are memory addresses of your char* elements. So, you would basically need your own comparator, which is not that hard to write. Or simply use std::string as key and whenever you need char* you just call string.c_str().

Upvotes: 1

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