How to use structs in C/C++?

The following is my code and I am getting some errors. Could someone help me understand these errors please?

Struct List :

struct List{      int size;      int arr[];   };  

Append Function :

int [] append(struct List a2, int a) {      int size = a2.size + sizeof(int);      int p [size]; //= (int *)malloc(size);      for(int i = 0; i < size; i++ ){          p[i] = a2.arr[i];          if (i > a2.size){              p[i] = a;          }         }      return p;  }  

Main Function :

int main(){      int arr[] = {12,313,13,214,23};      struct List a = {sizeof(arr)/sizeof(int), arr};      int narr [] = append(a, 50);      printf("%d\n" , sizeof(arr));     }  

The errors I'm getting are:

• "parentheses missing before [ "
• "int [] append(struct List a2, int a)"
• implicit function used in "int narr [] = append(a, 50)"

https://stackoverflow.com/questions/65786169/how-to-use-structs-in-c-c January 19, 2021 at 01:54PM