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));
}
}
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: {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.