用幾種迭代方式打印出TeeeMap中元素



// 1.第一種迭代方法
  Set<School> set = map.keySet();
  for (java.util.Iterator<School> it = set.iterator(); it.hasNext();) {
   System.out.println((School) it.next());
   
  }

// 2.第二種迭代方法
  Set<School> set1 = map.keySet();
  java.util.Iterator<School> it = set1.iterator();
  while (it.hasNext()) {
   System.out.println((School) it.next()); 
  }

//4.第三種迭代方法

    Set<School> set1 = map.keySet();
    Object[] school=set1.toArray();
    for(int i=0;i<set1.size();i++){
     System.out.println(school[i]);
     write((School)school[i],file);
    }

//4.第四種迭代方法
  for(School key:map.keySet()){
   System.out.println(key);
  }

//5.第五種迭代方法
  Iterator<Map.Entry<School,String>> p=map.entrySet().iterator();
  while(p.hasNext()){
   Map.Entry<School,String> entry=p.next();
   System.out.println(entry.getKey()+""+entry.getValue());
  }

//6.第六種迭代方法
  for(Map.Entry<School, String> entry:map.entrySet()){
   System.out.println(entry.getKey()+""+entry.getValue());
  }