different way of initializing variable?

This is a discussion on different way of initializing variable? within the C++ Programming forums, part of the General Programming Boards category; hi, i just read that you can initialize a variable int num = 10; like this int num(10) does any ...

  1. #1
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    different way of initializing variable?

    hi,

    i just read that you can initialize a variable

    int num = 10;

    like this

    int num(10)

    does any one ever do this ? are there any differences at all however subtle between the 2?

    Thanks.

  2. #2
    edk
    edk is offline
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    I do this as well.

    int num = 10; <-- creates the variable, initializes with the default value, then assigns 10 to it.

    int num(10); <-- creates the variable and initializes it with whatever's between the parentheses, using the constructor.

  3. #3
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    Re: different way of initializing variable?

    Originally posted by The Gweech
    hi,

    i just read that you can initialize a variable

    int num = 10;

    like this

    int num(10)

    does any one ever do this ? are there any differences at all however subtle between the 2?

    Thanks.
    That's (parantheses) the standard way to initialize a programmer defined class object, at least as far as I've learned .
    E.g., you create a class called Employee that contains first & last names & id #. When you create an object of class Employee, you can initialize it it like this:
    Code:
    Employee peon("Joe", "Sixpack", 666);
    A class is like a built in type (int, double, char, etc). There are probably differences, but that's what I've learned so far.

  4. #4
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    No Difference

    There is actually no real difference in the two different syntaxes, but the parenthetical syntax is required in the initialization lists for class constructors:


    class some_class
    {
    public:
    some_class() : varone(1), // Parentheses used here
    vartwo(2),
    varthree(3)
    {
    // Initialize...
    }
    private:
    int varone, vartwo, varthree;
    };

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