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Java List vs ArrayList

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有刺的猬
有刺的猬 2020-12-07 01:14

As a C++ oldtimer I have managed to solve my problem but I can not wrap my head around the underlying Java mechanisms here: 

Vector x = new Vec         


        
      
      
      

        

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                 既然无缘 
              
              
    
                
                   既然无缘
                                             
                
                
                (楼主)
            
              
                  
    
                2020-12-07 01:53
              
    

            
    
            
    
              
              

    List is an interface and an interface can't be instantiated.
    


    It's used to implement polymorphism. i.e. a reference of interface type can hold object of any class that implements it.
    


    List zzz = new ArrayList();



    it works, cause ArrayList implements List. 
    
    
    
             
    
                                                        
    
            
            
    
              
                
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