TWO ONE-DIMENSIONAL AARAYS

[size=2][b][color=Blue]Can some one give one c++ programming coding of two one-dimensional sample? I have task on it but have no idea how it goes..[/color][/b][/size]

Comments

  • 2 [italic]one dimensional arrays[/italic]? Or a [italic]two dimensional array[/italic]?

    one dimensional example. Declares an array of 10 elements and clears each element:

    [code]int array[10];

    for (int i=0; i<10; i++)
    array[i]=0;[/code]
    two dimensional example. Same thing as above but 2 dimensional:
    [code]int array[5][5];

    for (int y=0; y<5; y++)
    for (int x=0; x<5; x++)
    array[y][x]=0;[/code]

  • declaring a 3 rows and 4 columns two dimensional array of integers:

    int arr[3][4];

    accessing the integer in 0th row and 1st column: (array indices are 0 based)

    arr[0][1] = 10;

    printing all values of the array:
    [code]
    for (int i = 0; i < 3; i++) {
    for (int j = 0; j < 4; j++)
    cout << arr[i][j] << ' ';
    cout << endl;
    }
    [/code]

    --
    ~Donotalo()
  • : [size=2][b][color=Blue]Can some one give one c++ programming coding
    : of two one-dimensional sample? I have task on it but have no idea
    : how it goes..[/color][/b][/size]
    :
    It's a lot more complicated than it seems at first sight.

    Ypu can declare a 2 dimensional array like this

    int array[10][10];

    it works as you would expect. array[0][0] = 1; sets the top left-hand corner to 1.

    However generally we don't want arrays of fixed size, we want to build them dynamically. This is where the complication comes in. You need a array of pointers to pointers.

    In practise it is usally easier to say

    array = malloc(width * height * sizeof(int));

    array[y * width + x] = 1; /* set element x, y to one */

    handling the array as a one-dimensional object.

  • That isn't an array of pointer to pointer though, that's a "mangled" 2D array... which is better than pointer-to-pointer arrays in one way, you can memcpy() and strcpy() to and fro common (statically allocated) 2D arrays.
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