取所有的键: HashMap hm = new HashMap(); hm.put("A_thlsd,,", "01"); hm.put("b_adhd", "02"); hm.put("c_decteln", "03"); hm.put("d_apple", "04"); hm.put("e_blue", "05"); hm.put("ff_drag", "06"); hm.put("g_cellention", "07"); Set set = hm.keySet();Object[] obj=set.toArray(); Arrays.sort(obj); for(int i=0;i<obj.length;i++){ System.out.println(obj[i]); } 取所有的键值:HashMap hm = new HashMap(); hm.put("A_thlsd,,", "01"); hm.put("b_adhd", "02"); hm.put("c_decteln", "03"); hm.put("d_apple", "04"); hm.put("e_blue", "05"); hm.put("ff_drag", "06"); hm.put("g_cellention", "07"); Set set = hm.entrySet();Object[] obj=set.toArray(); //Arrays.sort(obj); for(int i=0;i<obj.length;i++){ System.out.println(obj[i]); } 这个方法不好
1. Set set = map.keySet(); Iterator it = set.iterator(); if(it.hasNext()){ Object j = it.next(); System.out.println(j); System.out.println(map.get(j)) ; } 2. Set set = map.entrySet(); Iterator it = set.iterator(); if(it.hasNext()){ Map.Entry me = (Map.Entry) it.next(); System.out.println(me.getKey()); System.out.println(me.getValue()); }
Set set = map.entrySet(); Iterator it = set.iterator(); if(it.hasNext()){ Map.Entry me = (Map.Entry) it.next(); System.out.println(me.getKey()+"="+me.getValue());
HashMap hm = new HashMap();
hm.put("A_thlsd,,", "01");
hm.put("b_adhd", "02");
hm.put("c_decteln", "03");
hm.put("d_apple", "04");
hm.put("e_blue", "05");
hm.put("ff_drag", "06");
hm.put("g_cellention", "07");
Set set = hm.keySet();Object[] obj=set.toArray();
Arrays.sort(obj);
for(int i=0;i<obj.length;i++){
System.out.println(obj[i]);
}
取所有的键值:HashMap hm = new HashMap();
hm.put("A_thlsd,,", "01");
hm.put("b_adhd", "02");
hm.put("c_decteln", "03");
hm.put("d_apple", "04");
hm.put("e_blue", "05");
hm.put("ff_drag", "06");
hm.put("g_cellention", "07");
Set set = hm.entrySet();Object[] obj=set.toArray();
//Arrays.sort(obj);
for(int i=0;i<obj.length;i++){
System.out.println(obj[i]);
}
这个方法不好
Set set = map.keySet();
Iterator it = set.iterator();
if(it.hasNext()){
Object j = it.next();
System.out.println(j);
System.out.println(map.get(j)) ;
}
2.
Set set = map.entrySet();
Iterator it = set.iterator();
if(it.hasNext()){
Map.Entry me = (Map.Entry) it.next();
System.out.println(me.getKey());
System.out.println(me.getValue());
}
Iterator it = set.iterator();
if(it.hasNext()){
Map.Entry me = (Map.Entry) it.next();
System.out.println(me.getKey()+"="+me.getValue());