I keep getting 'warning: control reaches end of non-void function' with this code:

Code:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

 if (section ==0)

 {
  return [comparativeList count];
 }

 if (section==1) 
 {
  return [generalList count];
 }

 if (section==2)
 {

  return [contactList
...