demo

    
    
    





    

        {{msg}}
        
 
        
count:{{count}}
        

        v-on  @click
        加值
        

        v-if
         

             count > 0 {{count}}
         
    
         

                count <0 {{count}}
         
         

         v-show
         
 COUNT > 0 了 
         

         v-for
         

                
{{item.name}}->{{item.age}}
         
        

            {{msg1}}