4

How to assign string value in multidimensional array, send the array as a function argument, and return it back to main function? I tried this but it gives an error:

char a[250][250][250];   // does not work
a[][0][2] = "0";         // does not work
a[][1][2] = "0";         // does not work

char a[][2][2] = {"0", "1"};  // works

// error: expected primary-expression before ']' token
a[i][j][max] = add_func(a[i][j][], i, j);
Gaurang Tandon
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sabbir
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3 Answers3

7

To initialize character strings table you can use curly braces. And the outer most dimension (I dont know how else can it be called) or the left most number in square is optional.

So this will work

char table[][3][10] = {
    {"row1-col1", "row1-col2", "row1-col3"},
    {"row2-col1", "row2-col2", "row2-col3"},
    {"row3-col1", "row3-col2", "row3-col3"},
    {"row4-col1", "row4-col2", "row4-col3"}
    };

You dont need to type table[4][3][10]. Compiler calculates it. The size of table is 120 bytes. As the contents are all string you can use 

char *table[][3] = ...

This will save 20% space.

Curly braces can only be used in initializing phase. Not after that. hence following code will not work.

a[][0][2] = "0";
Shiplu Mokaddim
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  • +1, and a mentor long ago called it the "superior" dimension of the array. All others he referred to as "inferior" dimensions. I've also seen them called "dominant" and "sub-dominant". – WhozCraig Dec 30 '12 at 10:12
6

After declaration you can not assign, but use strcpy()

char a[250][250][250];

strcpy(a[0][1],"0");

or assign at the time of declaration: 

char a[250][250][250] = {"0","2"};  
char a[][250][250] = {"0","2"};

or if you want to assign a single char. 

a[i][j][k] = '0';

Where i, j, k are any value less than 250

How to Declaration and Initialization 3D Array IN C

In-general a[3][4][2] is a three-dimension array, that can be view as

a[3][4][2] : Consist of 3 two-dimension arrays, where each 2-D array are consist of 4-rows and 2-colunms. can be declare as: 

char a[3][4][2] =  { 
                       { //oth 2-D array 
                         {"0"},
                         {"1"},
                         {"2"},
                         {"4"}
                       },
                       { //1th 2-D Array
                         {"0"},
                         {"1"},
                         {"2"},
                         {"4"}
                       },
                       { //2nd 2-D array
                         {"0"},
                         {"1"},
                         {"2"},
                         {"4"}
                       },
                   };

Note: "1" means two chars, one additional fro null ('\0') char.

If integer array: 

int a[3][2][3]=  
        {
            { //oth 2-D array, consists of 2-rows and 3-cols
            {11, 12, 13},
            {17, 18, 19}
            },
            {//1th 2-D array, consists of 2-rows and 3-cols
            {21, 22, 23},
            {27, 28, 29}
            },
            {//2th 2-D array, consists of 2-rows and 3-cols
            {31, 32, 33},
            {37, 38, 39}
            },
        };

Link to understand

Second error:

to this a[i][j][max] a char can assign not string so, 

a[i][j][max] = '0' ; // is correct  expression

but 

a[i][j][max] = "0";  // is not correct, wrong

Please read WhozCraig comment. you are declaring huge memory in stack!

According to your comment :

function declaration: 

char add_func(char a[250][250][250], int i, int j); // function definition

try like this: 

  char a[250][250][250];
  a[i][j][max] = add_func(a, i, j );
Community
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Grijesh Chauhan
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2

You probably would like to use pointers instead:

char *a[2][2] = { "0", "1", "2", "3" };
CubeSchrauber
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