How to initialize a 3-dimensional array [duplicate]

Answer 1

The dimension 1 is most peculiar; you also have one too many levels of braces:

double array[5][4][1]=
{
  // {  These braces mean what follows is meant to initialize array[0], but
  //    there are 5 initializers for the 4 elements in array[0], and there
  //    are 4 initializers for each of the 'size 1' sub-arrays which is why
  //    the compiler complains about too many initializers for array[0][0][0], etc.
    {1,2,3,4},
    {5,6,7,8},
    {9,10,11,12},
    {13,14,15,16},
    {17,18,19,20}
  // }
};

This would at least compile. The fully braced version would include a pair of braces around each number:

double array[5][4][1]=
{
    { {  1 }, {  2 }, {  3 }, {  4 }, },
    { {  5 }, {  6 }, {  7 }, {  8 }, },
    { {  9 }, { 10 }, { 11 }, { 12 }, },
    { { 13 }, { 14 }, { 15 }, { 16 }, },
    { { 17 }, { 18 }, { 19 }, { 20 }, },
};

That's 5 lines, with 4 sub-arrays on each line, and each sub-array contains a single number.

Answer 2

It is complaining because you said that your inner most array is only supposed to have a single element, yet you are giving it many.

int a[3][2][1] =                                                        
{                                                                       
    {                                                                   
        {1},                                                            
        {2}                                                             
    },                                                                  
    {                                                                   
        {3},                                                            
        {4}                                                             
    },                                                                  
    {                                                                   
        {5},                                                            
        {6}                                                             
    }                                                                   
}; 

If you want more inner elements, change your 1 to something else.