hashmap示例

HashMap類的remove()方法 (HashMap Class remove() method)

• remove() method is available in java.util package.

  remove()方法在java.util包中可用。

• remove() method is used to remove the key-value pairs that exist in this HashMap for the given key element (key_ele).

  remove()方法用于刪除給定鍵元素(key_ele)在此HashMap中存在的鍵值對。

• remove() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.

  remove()方法是一種非靜態方法，只能通過類對象訪問，如果嘗試使用類名稱訪問該方法，則會收到錯誤消息。

• remove() method does not throw an exception at the time of removing an element.

  remove()方法在刪除元素時不會引發異常。

Syntax:

句法：

    public Value remove(Object key_ele);

Parameter(s):

參數：

• Object key_ele – represents the key element whose associated key-value pair is to be deleted from this HashMap.

  對象key_ele –表示要從此HashMap中刪除其關聯的鍵值對的鍵元素。

Return value:

返回值：

The return type of the method is Value, it returns the associated value for the given key element when exists otherwise it returns null.

該方法的返回類型為Value ，如果存在則返回給定鍵元素的關聯值，否則返回null。

Example:

例：

// Java program to demonstrate the example 
// of Value remove(Object key_ele)
// method of HashMap 
import java.util.*;
public class RemoveOfHashMap {
public static void main(String[] args) {
// Instantiates a HashMap object
Map < Integer, String > map = new HashMap < Integer, String > ();
// By using put() method is to add
// key-value pairs in a HashMap
map.put(10, "C");
map.put(20, "C++");
map.put(50, "JAVA");
map.put(40, "PHP");
map.put(30, "SFDC");
// Display HashMap
System.out.println("HashMap: " + map);
// By using remove() method is to remove 
// the mappings exists for the given key
// element in this HashMap
map.remove(50);
// Display Modified HashMap
System.out.print("map.remove(50): " + map);
}
}

Output

輸出量

HashMap: {50=JAVA, 20=C++, 40=PHP, 10=C, 30=SFDC}
map.remove(50): {20=C++, 40=PHP, 10=C, 30=SFDC}

翻譯自: https://www.includehelp.com/java/hashmap-remove-method-with-example.aspx

hashmap示例