Java Hashtable putAll（）方法与示例

梦里梦外; 2023-03-05 15:53 51阅读 0赞

## 哈希表类putAll()方法 **(**Hashtable Class putAll() method**)** ##

*  **putAll() method** is available in java.util package.
    
    **putAll()方法**在java.util包中可用。
 *  **putAll() method** is used to copy all the mappings that exist from the given Map to this Hashtable.
    
    **putAll()方法**用于将给定Map中存在的所有映射复制到此Hashtable中。
 *  **putAll() 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.
    
    **putAll()方法**是一种非静态方法，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。
 *  **putAll() method** does not throw an exception at the time of copying mappings.
    
    **putAll()方法**在复制映射时不会引发异常。

**Syntax:**

**句法：**

public void putAll(Map m);

**Parameter(s):**

**参数：**

*  Map m – the mappings to be exists in this Map (m).
    
    映射m –该映射(m)中将存在的映射。

**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 putAll(Map m) method of Hashtable 
    
    import java.util.*;
    
    public class PutAllOfHashtable {
        
        public static void main(String[] args) {
        
            //Instantiate a linked hashmap
            //and hashtable object  
            Map lhm = new LinkedHashMap();
            Hashtable ht = new Hashtable();
    
            // By using put() method is to
            // add the linked values in an
            // linked hashmap lhm
            lhm.put(10, "C");
            lhm.put(20, "C++");
            lhm.put(30, "JAVA");
            lhm.put(40, "PHP");
            lhm.put(50, "SFDC");
    
            // Display linked hashmap
            System.out.println("lhm: " + lhm);
    
            // By using putAll() method is to 
            // copy all of the key-value pairs
            // exists in this linked hashmap and
            // paste it into this Hashtable
    
            ht.putAll(lhm);
    
            // Display Hashtable
            System.out.println("ht.putAll(lhm): " + ht);
        }
    }

**Output**

**输出量**

lhm: {10=C, 20=C++, 30=JAVA, 40=PHP, 50=SFDC}
    ht.putAll(lhm): {10=C, 20=C++, 30=JAVA, 40=PHP, 50=SFDC}

> 翻译自: [https://www.includehelp.com/java/hashtable-putall-method-with-example.aspx][https_www.includehelp.com_java_hashtable-putall-method-with-example.aspx]

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