如何在Java中创建 TreeMap?
Java中的TreeMap用于实现 地图界面 和NavigableMap以及Abstract Class 。映射根据其键的自然顺序进行排序,或者通过映射创建时提供的Comparator进行排序,具体取决于使用的构造函数。
要创建 TreeMap,我们可以使用Map 类或TreeMap 类引用。
示例 1:
Java
// Java program demonstrate how to create a TreeMap
import java.util.*;
class GFG {
public static void main(String[] args)
{
// Declaring a treemap
TreeMap map;
// Creating an empty TreeMap
map = new TreeMap();
System.out.println("TreeMap successfully"
+ " created");
}
}
Java
// Java program demonstrate how to create and add elements
// to TreeMap
import java.util.*;
class GFG {
public static void main(String[] args)
{
// Creating an empty TreeMap using Map interface
Map map = new TreeMap<>();
System.out.println("TreeMap successfully"
+ " created");
// Adding elements
map.put(1, "Geeks");
map.put(2, "for");
map.put(3, "Geeks");
// Printing TreeMap
System.out.println("TreeMap: " + map);
}
}
输出
TreeMap successfully created
示例 2:
Java
// Java program demonstrate how to create and add elements
// to TreeMap
import java.util.*;
class GFG {
public static void main(String[] args)
{
// Creating an empty TreeMap using Map interface
Map map = new TreeMap<>();
System.out.println("TreeMap successfully"
+ " created");
// Adding elements
map.put(1, "Geeks");
map.put(2, "for");
map.put(3, "Geeks");
// Printing TreeMap
System.out.println("TreeMap: " + map);
}
}
输出
TreeMap successfully created
TreeMap: {1=Geeks, 2=for, 3=Geeks}