Java HashMap.get() – Examples
In this tutorial, we will learn about the Java HashMap.get() function, and learn how to use this function to get the value of specific key, with the help of examples.
get(Object key)
HashMap.get() Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key.
Syntax
The syntax of get() function is
get(Object key)
where
Parameter | Description |
---|---|
key | The key whose value in this HashMap has to be returned. |
Returns
The function returns value.
Example 1 – get(Object key) – Key Present
In this example, we will initialize a HashMap hashMap
with mappings from Integer to String. To get the value corresponding to key “3”, we will use HashMap.get() method.
Java Program
import java.util.HashMap; public class Example{ public static void main(String[] args) { HashMap<Integer, String> hashMap = new HashMap<>(); hashMap.put(1, "A"); hashMap.put(2, "B"); hashMap.put(3, "C"); hashMap.put(4, "D"); int key = 2; String value = hashMap.get(key); System.out.println("The value for key \"" + key + "\" is : " + value); } }
Output
The value for key "2" is : B
Example 2 – get(Object key) – Key not Present
In this example, we will initialize a HashMap hashMap
with mappings from Integer to String. To get the value corresponding to key “5”, we will use HashMap.get() method. Since, the specified key is not present in this HashMap, get() returns null.
Java Program
import java.util.HashMap; public class Example{ public static void main(String[] args) { HashMap<Integer, String> hashMap = new HashMap<>(); hashMap.put(1, "A"); hashMap.put(2, "B"); hashMap.put(3, "C"); hashMap.put(4, "D"); int key = 5; String value = hashMap.get(key); System.out.println("The value for key \"" + key + "\" is : " + value); } }
Output
The value for key "5" is : null
Conclusion
In this Java Tutorial, we have learnt the syntax of Java HashMap.get() function, and also learnt how to use this function with the help of examples.