arrp | Programming language for stream processing

Filtering twice may be more readable.

Simply do a split on ,. Because split(), divides a String into an ordered set of substrings, puts these substrings into an array, and returns the array and that's what you want

See Go CommonMistakes: Using reference to loop iterator variable

why address is the same?

The value of k is updated as the loop advances forward.

why the value of arrP[0] is not 1?

Same as the above.

To demonstrate with a modified-version of the example that you provided:

Remove echo from echo call_user_func_array($fName, $arrP);. Just use call_user_func_array($fName, $arrP);

You're passing MMULT the wrong kind of array. This is a worksheet function, not a VBA function. The worksheet version of an array is a range of cells, so put the values into two worksheet ranges and refer to them there.

For example, part of your code might be:

When you are getting the input using %s in character type variable, the memory adjacent to the address of the char variable gets overwritten thus can cause program crash. if you want to enter a string, you can try it by defining an array of characters (as char my name[MAX], MAX can be a size suitable to you).

arr is a local variable inside the moveOver() function. Assigning to it has no effect on the variables in main(). And in main(), arr is an array, not a pointer, so you can't reassign it to point to a different array.

You need to change moveOver() so it takes a reference. Then you can pass arrptr to it, and the function will be able to reassign it.

See Pass by Reference / Value in C++

Another problem you have is that *arr = *arrp; doesn't copy the whole array, it just copies the first element of the array. But there's no need to allocate a new array for arr at all; you can simply do arr = arrp; to copy the pointers.