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    IdentityHashMap类的java.util.IdentityHashMap.get() 方法用于检索或获取由参数中提到的特定键映射的值。当map不包含密钥的这种映射时,它返回NULL。

    句法:

    IdentityHashMap.get(Object key_element

    参数:该方法采用对象类型的一个参数key_element,并引用应该获取其关联值的键。

    返回值:该方法返回与参数中的key_element关联的值。

    下面的程序说明了java.util.IdentityHashMap.get()方法的工作原理

    程序1:

    // Java code to illustrate the get() method
    import java.util.*;
    
    public class Identity_Hash_Map_Demo {
        public static void main(String[] args)
        {
    
            // Creating an empty IdentityHashMap
            Map<Integer, String> identity_hash = 
                  new IdentityHashMap<Integer, String>();
    
            // Mapping string values to int keys
            identity_hash.put(10, "Geeks");
            identity_hash.put(15, "4");
            identity_hash.put(20, "Geeks");
            identity_hash.put(25, "Welcomes");
            identity_hash.put(30, "You");
    
            // Displaying the IdentityHashMap
            System.out.println("Initial Mappings are: " + 
                                           identity_hash);
    
            // Getting the value of 25
            System.out.println("The Value is: " + 
                                    identity_hash.get(25));
    
            // Getting the value of 10
            System.out.println("The Value is: " + 
                                    identity_hash.get(10));
        }
    }
    

    输出:

    Initial Mappings are: {10=Geeks, 30=You, 20=Geeks, 25=Welcomes, 15=4}
    The Value is: Welcomes
    The Value is: Geeks

    程序2:

    // Java code to illustrate the get() method
    import java.util.*;
    
    public class Identity_Hash_Map_Demo {
        public static void main(String[] args)
        {
    
            // Creating an empty IdentityHashMap
            Map<String, Integer> identity_hash = 
                   new IdentityHashMap<String, Integer>();
    
            // Mapping int values to string keys
            identity_hash.put("Geeks", 10);
            identity_hash.put("4", 15);
            identity_hash.put("Geeks", 20);
            identity_hash.put("Welcomes", 25);
            identity_hash.put("You", 30);
    
            // Displaying the IdentityHashMap
            System.out.println("Initial Mappings are: " + 
                                           identity_hash);
    
            // Getting the value of "Geeks"
            System.out.println("The Value is: " + 
                              identity_hash.get("Geeks"));
    
            // Getting the value of "You"
            System.out.println("The Value is: " + 
                                identity_hash.get("You"));
        }
    }
    

    输出:

    Initial Mappings are: {Geeks=20, Welcomes=25, You=30, 4=15}
    The Value is: 20
    The Value is: 30

     
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