Question

Suppose a structure defined as below is allocated dynamically in an array. Would the type, label and description need to null terminated in order to safely delete the allocated structures?

struct operation_data
{
    int number;             
    char* type;             
    char* label;                
    char* description;
}

operation *data=new operation_data[5];  
for (int i=0; i<5; i++)
{
    data[i].type=new char[250];
    data[i].label=new char[250];
    data[i].description=new char[250];
}    
for (int i=0; i<5; i++)
{
    if (data[i].type) delete[] data[i].type;
    if (data[i].label) delete[] data[i].label;
    if (data[i].description) delete[] data[i].description;    
}

My code represents the snippet above. this is causing a Heap corruption detected error in the second delete statement. Please help me rectify this.

Answer 1

no, they dont need to be null terminated. null termination is only an indicator where the string inside the char array ends.

i would recommend to add a ctor and dtor to your struct to safely delete it.

struct operation {
  int number;
  char* type;
  char* label;
  char* description;

  operation() : type(0), label(0), description(0) {}
  ~operation() {
    if( type )
          delete[] type;
    if( label )
      delete[] label;
    if( description )
      delete[] description;
  }
};