java 手工实现HashSet

Posted 2022-04-30

底层是用HashMap来实现

HashMap map;
    private static final int VALUE=10;
    public test()
    
        map=new HashMap();
    

public void add(Object obs)     //将输入的值作为HashMap的键，从而达到不重复

    map.put(obs, VALUE);

public int size()

    return map.size();


public String toString()

    StringBuilder ss=new StringBuilder();
    for(Object s:map.keySet())
    
        ss.append(s+",");
    
    ss.setCharAt(ss.length()-1, ‘ ‘);
    return ss.toString();