Thread: array as an argument

  1. #1
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    array as an argument

    Say in main I have:
    PHP Code:
    int nums[5];

    set_numbers(nums); 
    and I have a function called set_numbers() where I want to set the values for the numbers in the array:
    PHP Code:
    void set_numbers(int n[])
    {
         
    n[0] = 1;
         
    n[1] = 2;
         
    n[2] = 3;
         
    n[3] = 4;
         
    n[5] = 5;

    that code works, but everywhere I read that you have to pass arrays by reference, and when I try to do that I get an error. Whats wrong with doing it how I'm doing it now, and how do I pass it by reference instead?

  2. #2
    Sweet
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    Nothing thats the perfect way to do it.
    Woop?

  3. #3
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    hmm.. ok well.. then can someone tell me how to make the iint nums[5] array in main the default array to use?

  4. #4
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    arrays are always passed by reference. What do u mean by default array?

  5. #5
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    like if i were passing an int i could do
    PHP Code:
    void set_numbers(int j 1){} 
    i want to set the default value for int n[] to the array nums[] in the main function. can anyone tell me how to do that.

  6. #6
    Sweet
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    No way really to do that. A smart person always passes the size of the array as an parameter.
    Woop?

  7. #7
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    well then how would i get around that? I have a dll and I have an exe that tell the dll to create an instance of a class and i have to save that instance inside a vector. So don't I have to use a default vector?

  8. #8
    Sweet
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    Huh? If you are using a vector then use .size().
    Woop?

  9. #9
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    no. i'm not talking about the size. i'm talking about when i want to insert into a vector. the vector is outside of the function so how do i pass that vector to the function so i can insert the new instance in it?

  10. #10
    Slave MadCow257's Avatar
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    judging from your original post maybe you mean something like this??
    Code:
    #include <iostream>
    void set_numbers(int * ptr);
    int main()
    {
    	int * ptr = new int[5];
    	set_numbers(ptr);
    	std::cout << ptr[2];
    	delete ptr;
    }
    void set_numbers(int * ptr)
    {
    	ptr[2] = 11;
    }

  11. #11
    Sweet
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    Or if you want to pass the vector
    Code:
    void function(std::vector<type> &toPass);
    Woop?

  12. #12
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    hmm. i shouldn't have said anything about the main function because this question isn't literal. its in a dll and there is no main function. i have a vector that i create at the start and whenever the exe calls a function i want it to add an instance to that vector. prog-bman is that what you're suggestion will do?

  13. #13
    Sweet
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    Yes that will pass a vector from a function to another function and modify the contents within that vector.
    Woop?

  14. #14
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    i have a question though, what if i can't pass the vector from the exe that is calling the function?

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