Java中的 TreeMap clone() 方法及示例

在Java中，TreeMap 类的 clone() 方法用于返回提到的树图的浅表副本。它只是创建地图的副本。

--> java.util Package
    --> TreeMap Class
        --> clone() Method 

句法：

Tree_Map.clone()

参数：该方法不带任何参数。

返回类型： TreeMap 的副本。

示例 1：将字符串值映射到整数键

Java

// Java Program to Illustrate clone() method
// of TreeMap class
 
// Importing required classes
import java.util.*;
 
// Main class
public class GFG {
 
    // Main driver method
    public static void main(String[] args)
    {
        // Creating an empty TreeMap by
        // declaring object of integer-string pairs
        TreeMap tree_map
            = new TreeMap();
 
        // Mapping string values to int keys
        // using put() method
        tree_map.put(10, "Geeks");
        tree_map.put(15, "4");
        tree_map.put(20, "Geeks");
        tree_map.put(25, "Welcomes");
        tree_map.put(30, "You");
 
        // printing all elements of TreeMap
        System.out.println("Initial Mappings are: "
                           + tree_map);
 
        // Displaying the cloned TreeMap
        // using clone()
        System.out.println("The cloned map look like this: "
                           + tree_map.clone());
    }
}

输出

Initial Mappings are: {10=Geeks, 15=4, 20=Geeks, 25=Welcomes, 30=You}
The cloned map look like this: {10=Geeks, 15=4, 20=Geeks, 25=Welcomes, 30=You}

示例 2：将整数值映射到字符串键

Java

// Java Program  to Illustrate clone() Method
// of TreeMap class
 
// Importing required classes
import java.util.*;
 
// Main class
public class GFG {
 
    // Main driver method
    public static void main(String[] args)
    {
        // Creating an empty TreeMap
        TreeMap tree_map
            = new TreeMap();
 
        // Mapping int values to string keys
        // using put() method
        tree_map.put("Geeks", 10);
        tree_map.put("4", 15);
        tree_map.put("Geeks", 20);
        tree_map.put("Welcomes", 25);
        tree_map.put("You", 30);
 
        // Displaying all elements initial mapping TreeMap
        System.out.println("Initial Mappings are: "
                           + tree_map);
 
        // Displaying the cloned TreeMap
        // using clone()
        System.out.println("The cloned map look like this: "
                           + tree_map.clone());
    }
}

输出

Initial Mappings are: {4=15, Geeks=20, Welcomes=25, You=30}
The cloned map look like this: {4=15, Geeks=20, Welcomes=25, You=30}

Note: Similarly the same operation can be performed with any type of Mappings with variation and combination of different data types.