LinkedHashMap是Map接口的哈希表和链表实现。 LinkedHashMap
类不提供排序为TreeMap,但它在插入元素时保持元素的顺序。
在下面的示例中,我们将展示LinkedHashMap
类的各种方法。如下所示:
put()
- 将键和值添加到Map中。get()
- 通过传递键返回值。remove()
- 从Map中删除键和值。size()
- 返回Map的大小。containsKey()
- 如果key存在于map中则返回true,否则返回false。containsValue()
- 如果map中存在value则返回true,否则返回false。clear()
- 从Map中删除所有元素
文件:LinkedHashMapExample.java -
package com.yiibai.tutorial;
import java.util.LinkedHashMap;
import java.util.Map;
/**
* @author yiibai
*
*/
public class LinkedHashMapExample {
public static void main(String[] args) {
Map<String String> map=new LinkedHashMap<>();
/*Adding key and values in LinkedHashMap*/
map.put("1" "One");
map.put("2" "Two");
map.put("3""Three");
map.put("4" "Four");
map.put("5" "Five");
System.out.println("LinkedHashMap key-values:"+map);
/*Get value by key from the LinkedHashMap*/
System.out.println("Value of '4' is: "+map.get("4"));
/*Removing key and value from the LinkedHashMap */
map.remove("4");
System.out.println("After removal LinkedHashMap Key-Value: " +map);
/*Getting size of LinkedHashMap*/
System.out.println("Size of LinkedHashMap is : "+map.size());
/*Checking if key exist in the LinkedHashMap or not*/
System.out.println("Key '3' exist: "+map.containsKey("3"));
/*Checking if value exist in the LinkedHashMap or not*/
System.out.println("Key '6' exist: "+map.containsValue("6"));
/*Remove all keys and values from the LinkedHashMap*/
map.clear();
System.out.println("After clearing LinkedHashMap: "+map);
}
}
执行上面代码,得到以下结果:
LinkedHashMap key-values:{1=One 2=Two 3=Three 4=Four 5=Five}
Value of '4' is: Four
After removal LinkedHashMap Key-Value: {1=One 2=Two 3=Three 5=Five}
Size of LinkedHashMap is : 4
Key '3' exist: true
Key '6' exist: false
After clearing LinkedHashMap: {}