用Java创建TreeMap并添加键值对
TreeMap不能包含重复的键。TreeMap不能包含null键。但是，它可以具有空值。
首先让我们看看如何创建TreeMap-
TreeMap<Integer,String> m = new TreeMap<Integer,String>();
以键值对的形式添加一些元素-
m.put(1,"India"); m.put(2,"US"); m.put(3,"Australia"); m.put(4,"Netherlands"); m.put(5,"Canada");
以下是创建TreeMap并添加键值对的示例-
示例
import java.util.*;
public class Demo {
public static void main(String args[]) {
TreeMap<Integer,String> m = new TreeMap<Integer,String>();
m.put(1,"India");
m.put(2,"US");
m.put(3,"Australia");
m.put(4,"Netherlands");
m.put(5,"Canada");
for(Map.Entry e:m.entrySet()) {
System.out.println(e.getKey()+" "+e.getValue());
}
}
}输出结果
1 India 2 US 3 Australia 4 Netherlands 5 Canada