Thread: copying an **int array passed through parameters

  1. #1
    Registered User
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    Aug 2005
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    copying an **int array passed through parameters

    Is there any other way to copy an array or rather 'pass by value'?

    Heres what im currently doing, I do not like it much... (I need to work with the data in array but I can't have it changed once the method returns.

    Code:
    int dijkstra(int buildings,int **tempEdges)
    {
        //crude way of copying an array
      	int **edges;
    	edges = new int*[buildings+1];
    	for(int i=0;i <= buildings;++i)
    		edges[i] = new int[buildings+1];
    	for(int i=0;i <= buildings;++i)
    	for(int j=0;j <= buildings;++j)
    		edges[i][j] = tempEdges[i][j];
    
    //jumble array around to work with it
    //return value
    }
    Any ideas?

  2. #2
    Registered User
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    For primitive and POD types you can use the C function memcpy to copy blocks of continuous memory.
    It is too clear and so it is hard to see.
    A dunce once searched for fire with a lighted lantern.
    Had he known what fire was,
    He could have cooked his rice much sooner.

  3. #3
    C++まいる!Cをこわせ!
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    I'd use a std::vector. Every element in the vector will be copied if you pass it by value.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

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