Java中的 LinkedHashMap get() 方法及示例

在Java中，LinkedHashMap 类的get() 方法用于检索或获取参数中提到的特定键映射的值。当映射不包含键的此类映射时，它返回 NULL。

--> java.util Package
    --> LinkedHashMap Class
         --> get() Method  

句法：

Linked_Hash_Map.get(Object key_element)

参数：对象类型的一个参数key_element ，指的是应该获取其关联值的键。

返回类型：与参数中的key_element关联的值。

示例 1：将字符串值映射到整数键。

Java

// Java Program to illustrate get() method
// of LinkedHashMap
// Mapping String Values to Integer Keys
  
// Importing required classes
import java.util.*;
  
// Main class
public class GFG {
  
    // Main driver method
    public static void main(String[] args)
    {
  
        // Creating an empty HashMap
        LinkedHashMap li_hash_map
            = new LinkedHashMap();
  
        // Mapping string values to int keys
        // using put() method
        li_hash_map.put(10, "Geeks");
        li_hash_map.put(15, "4");
        li_hash_map.put(20, "Geeks");
        li_hash_map.put(25, "Welcomes");
        li_hash_map.put(30, "You");
  
        // Printing all elements of LinkedHashMap
        System.out.println("Initial Mappings are: "
                           + li_hash_map);
  
        // Getting the value of 25
        System.out.println("The Value is: "
                           + li_hash_map.get(25));
  
        // Getting the value of 10
        System.out.println("The Value is: "
                           + li_hash_map.get(10));
    }
}

输出：

Initial Mappings are: {10=Geeks, 15=4, 20=Geeks, 25=Welcomes, 30=You}
The Value is: Welcomes
The Value is: Geeks

示例 2：将整数值映射到字符串键

Java

// Java Program to Illustrate get() method
// Mapping Integer Values to String Keys
  
// Importing required classes
import java.util.*;
  
// Main class
public class Linked_Hash_Map_Demo {
  
    // Main driver method
    public static void main(String[] args)
    {
  
        // Creating an empty LinkedHashMap
        LinkedHashMap li_hash_map
            = new LinkedHashMap();
  
        // Mapping int values to string keys
        // using put() method
        li_hash_map.put("Geeks", 10);
        li_hash_map.put("4", 15);
        li_hash_map.put("Geeks", 20);
        li_hash_map.put("Welcomes", 25);
        li_hash_map.put("You", 30);
  
        // Printing all elements of LinkedHashMap
        System.out.println("Initial Mappings are: "
                           + li_hash_map);
  
        // Getting the value of "Geeks"
        System.out.println("The Value is: "
                           + li_hash_map.get("Geeks"));
  
        // Getting the value of "You"
        System.out.println("The Value is: "
                           + li_hash_map.get("You"));
    }
}

输出：

Initial Mappings are: {Geeks=20, 4=15, Welcomes=25, You=30}
The Value is: 20
The Value is: 30

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