C compile error: “Variable-sized object may not be initialized”

Question

Why do I receive the error \"Variable-sized object may not be initialized\" with the following code?

int boardAux[length][length] = {{0}};

Answer 1

The array is not initialized with the memory specified anf throws an error variable sized array may not be initialised I prefer usual way of initialization,

for (i = 0; i <= bins; i++)
        arr[i] = 0;

Answer 2

You receive this error because in C language you are not allowed to use initializers with variable length arrays. The error message you are getting basically says it all.

6.7.8 Initialization

...

3 The type of the entity to be initialized shall be an array of unknown size or an object type that is not a variable length array type.

Answer 3

After declaring the array

int boardAux[length][length];

the simplest way to assign the initial values as zero is using for loop, even if it may be a bit lengthy

int i, j;
for (i = 0; i<length; i++)
{
    for (j = 0; j<length; j++)
        boardAux[i][j] = 0;
}

Answer 4

For C++ separate declaration and initialization like this..

int a[n][m] ;
a[n][m]= {0};

Answer 5

Simply declare length to be a cons, if it is not then you should be allocating memory dynamically

Answer 6

You cannot do it. C compiler cannot do such a complex thing on stack.

You have to use heap and dynamic allocation.

What you really need to do:

• compute size (nmsizeof(element)) of the memory you need
• call malloc(size) to allocate the memory
• create an accessor: int* access(ptr,x,y,rowSize) { return ptr + y*rowSize + x; }

Use *access(boardAux, x, y, size) = 42 to interact with the matrix.