hashmap示例_Java HashMap clear（）方法与示例

╰+攻爆jí腚メ 2023-03-05 12:53 2阅读 0赞

hashmap示例

## HashMap类的clear()方法 **(**HashMap Class clear() method**)** ##

*  **clear() method** is available in java.util package.
    
    **clear()方法**在java.util包中可用。
 *  **clear() method** is used to clear all of the associations or mappings that exist from this HashMap.
    
    **clear()方法**用于清除此HashMap中存在的所有关联或映射。
 *  **clear() 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.
    
    **clear()方法**是一个非静态方法，只能通过类对象访问，如果尝试使用类名称访问该方法，则会收到错误消息。
 *  **clear() method** does not throw an exception at the time of clearing elements.
    
    **clear()方法**在清除元素时不会引发异常。

**Syntax:**

**句法：**

public void clear();

**Parameter(s):**

**参数：**

*  It does not accept any parameter.
    
    它不接受任何参数。

**Return value:**

**返回值：**

The return type of the method is void, it returns nothing.

该方法的返回类型为void ，不返回任何内容。

**Example:**

**例：**

// Java program to demonstrate the example 
    // of void clear() method of HashMap 
    
    import java.util.*;
    
    public class ClearOfHashMap {
        
        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 TreeMap
            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 clear() method is
            // to remove the mappings exists
            // in this HashMap
            map.clear();
    
            System.out.print("map.clear(): ");
            System.out.println(map);
        }
    }

**Output**

**输出量**

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

> 翻译自: [https://www.includehelp.com/java/hashmap-clear-method-with-example.aspx][https_www.includehelp.com_java_hashmap-clear-method-with-example.aspx]

hashmap示例

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