Infinite folding menu sample code rewritten from js general method to object-oriented method_javascript skills

This example is based on someone else's example. It turns out that guy used a general method to write an infinite folding menu. I would like to thank him in advance! Later, I made some simplified modifications and changed the original example into an object-oriented approach. The small expanded and closed icons in the example can be re-added by myself to better view the effect.

Copy code The code is as follows:

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  校讯通
  
  
  
  • 
    沈阳市
    
    
    
    • 
      二小
      
      
      
      • 二年级
      
      
      • 
        三年级
        
        
        
        • 
          一班
          
          
          
          • 张三
          
          
          • 
            王五
            
            
            
            • 班长
            
            
            • 学习委员
            
            
            
            
          
          
          
          
        
        
        • 实验班
        
        
        
        
      
      
      
      
    
    
    
    
  
  
  • 
    抚顺市
    
    
    
    • 二小
    
    
    • 一中
    
    
    
    
  
  
  
  

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