hashmap clone_Java HashMap clone（）方法与示例

逃离我推掉我的手 2023-03-05 12:53 9阅读 0赞

hashmap clone

## HashMap类clone()方法 **(**HashMap Class clone() method**)** ##

*  **clone() method** is available in java.util package.
    
    **clone()方法**在java.util包中可用。
 *  **clone() method** is used to get a cloned copy of this HashMap instance or in other words, we can say it returns a shallow copy of this HashMap.
    
    **clone()方法**用于获取此HashMap实例的克隆副本，换句话说，可以说它返回此HashMap的浅表副本。
 *  **clone() 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.
    
    **clone()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。
 *  **clone() method** does not throw an exception at the time of cloning an object.
    
    **clone()方法**在克隆对象时不会引发异常。

**Syntax:**

**句法：**

public Object clone();

**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 Object, it clones this HashMap.

该方法的返回类型为Object ，它将克隆此HashMap。

**Example:**

**例：**

// Java program to demonstrate the example 
    // of Object clone() method of HashMap 
    
    import java.util.*;
    
    public class CloneOfHashMap {
        
        public static void main(String[] args) {
        
            // Instantiates a HashMap object
            HashMap < Integer, String > hm = new HashMap < Integer, String > ();
            HashMap < Integer, String > clone_map = new HashMap < Integer, String > ();
    
            // By using put() method is to add
            // key-value pairs in a TreeMap
            hm.put(10, "C");
            hm.put(20, "C++");
            hm.put(50, "JAVA");
            hm.put(40, "PHP");
            hm.put(30, "SFDC");
    
            // Display HashMap and clone_map
            System.out.println("HashMap: " + hm);
            System.out.println("CloneMap: " + clone_map);
    
            // By using clone() method is to clone
            // this object
            clone_map = (HashMap) hm.clone();
    
            //Display clone_map
            System.out.println("hm.clone(): " + clone_map);
        }
    }

**Output**

**输出量**

HashMap: {50=JAVA, 20=C++, 40=PHP, 10=C, 30=SFDC}
    CloneMap: {}
    hm.clone(): {40=PHP, 50=JAVA, 10=C, 20=C++, 30=SFDC}

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

hashmap clone

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