Thread: Class Questions

  1. #1
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    Class Questions

    I have a simple question from a class of mine on dynamic arrays.

    When allocating an array of objects, what constructor is used to initialize all of the objects in the array?

    A. The automatic copy constructor
    B. The constructor specified at the declaration
    C. The default constructor
    D. None of the above

    What are your thoughts on this question?

    I was learning towards B, but then I wasn't sure.

    Thanks!

    -Shane

  2. #2
    Senior Member joshdick's Avatar
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    My vote is for C.
    FAQ

    "The computer programmer is a creator of universes for which he alone is responsible. Universes of virtually unlimited complexity can be created in the form of computer programs." -- Joseph Weizenbaum.

    "If you cannot grok the overall structure of a program while taking a shower, you are not ready to code it." -- Richard Pattis.

  3. #3
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    Alright, I have another one that I'm kinda stuck on

    Which situation does not use the copy constructor?

    A. Calling a function with a reference parameter
    B. Calling a function with a value parameter
    C. Declaring a variable to be a copy of another existing object
    D. Returning a value from a function
    E. All of the above situations use the copy constructor

    I'm thinking that it is E, but I didn't know whether a value parameter is copied or not

  4. #4
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    When allocating an array of objects, the default constructor is used.

    As for the last question, the copy constructor is not used when passing by reference.

  5. #5
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    Alright, this one is really stumping me

    What is the usual worst-case performance for resizing a container class that stores its data in a dynamic array?

    A. Constant Time
    B. Logarithmic Time
    C. Linear Time
    D. Quadratic Time

    Any helpful information on this question would be appreciated.

  6. #6
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    When allocating an array of class objects, the constructor which takes no parameters is called, either the default or the user defined constructor. As usual if no, 'no parameters constructor' is defined but a constructor that does take parameters is defined, that will result in a compiler error

    as for the worst case one, i think it's the quadratic, although i'm not too sure.

  7. #7
    Guest Sebastiani's Avatar
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    Instead of asking others for answers to your homework, perhaps you should actually do some research of your own. Besides, it's against board rules.
    Code:
    #include <cmath>
    #include <complex>
    bool euler_flip(bool value)
    {
        return std::pow
        (
            std::complex<float>(std::exp(1.0)), 
            std::complex<float>(0, 1) 
            * std::complex<float>(std::atan(1.0)
            *(1 << (value + 2)))
        ).real() < 0;
    }

  8. #8
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    Alright how about this.

    How do you calculate worst case performance for a given function?


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