how to de-reference a pointer to a map

This is a discussion on how to de-reference a pointer to a map within the C++ Programming forums, part of the General Programming Boards category; Hi If I have a pointer to a map container: Code: map<int, double>* mapPointer = &aMap; how do I then ...

  1. #1
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    how to de-reference a pointer to a map

    Hi

    If I have a pointer to a map container:

    Code:
    map<int, double>* mapPointer = &aMap;
    how do I then de-reference the pointer to access a member through its key?

    Code:
    double a = map[4]; // works
    double b = mapPointer*[4]; // incorrect - how do I do this?
    thanks

  2. #2
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    Same way you would do any other object, put the * in front:
    Code:
    double c = (*mapPointer)[4];
    >> double a = map[4]; // works
    BTW, that should be "compiles", not "works", since it of course does not actually work.

  3. #3
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    many thanks

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