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Why is List not a sub-type of List<Object>?

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你的背包
你的背包 2020-12-10 05:43 
public void wahey(List list) {}

wahey(new LinkedList());



The call to the method will not type-check. I can\'t even cas         


        
      
      
      

        

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                 旧时难觅i 
              
              
    
                
                   旧时难觅i
                                             
                
                
                (楼主)
            
              
                  
    
                2020-12-10 06:35
              
    

            
    
            
    
              
              

    Consider if it was...
    


    List nums = new ArrayList();
List objs = nums
objs.add("Oh no!");
int x = nums.get(0); //throws ClassCastException



    You would be able to add anything of the parent type to the list, which may not be what it was formerly declared as, which as the above example demonstrates, causes all sorts of problems.  Thus, it is not allowed.
    
    
    
             
    
                                                        
    
            
            
    
              
                
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