Java HashMap get()

import java.util.HashMap;

class Main {
  public static void main(String[] args) {
    // create an HashMap
    HashMap<Integer, String> numbers = new HashMap<>();
    numbers.put(1, "Java");
    numbers.put(2, "Python");
    numbers.put(3, "JavaScript");

    // get the value with key 1
    String value = numbers.get(1);

    System.out.println("HashMap Value with Key 1: " + value);
  }
}

// Output: HashMap Value with Key 1: Java

Syntax of HashMap get()

The syntax of the get() method is:

hashmap.get(Object key)

Here, hashmap is an object of the HashMap class.

get() Parameters

The get() method takes a single parameter.

• key - key whose mapped value is to be returned

get() Return Value

• returns the value to which the specified key is associated

Note: The method returns null, if either the specified key is mapped to a null value or the key is not present on the hashmap.

Example 1: Get String Value Using Integer Key

import java.util.HashMap;

class Main {
  public static void main(String[] args) {
    // create an HashMap
    HashMap<Integer, String> numbers = new HashMap<>();

    // insert entries to the HashMap
    numbers.put(1, "Java");
    numbers.put(2, "Python");
    numbers.put(3, "JavaScript");
    System.out.println("HashMap: " + numbers);

    // get the value
    String value = numbers.get(3);
    System.out.println("The key 3 maps to the value: " + value);

  }
}

Output

HashMap: {1=Java, 2=Python, 3=JavaScript}
The key 3 maps to the value: JavaScript

In the above example, we have created a hashmap named numbers. The get() method is used to access the value Java to which the key 1 is associated with.

Note: We can use the HashMap containsKey() method to check if a particular key is present in the hashmap.

Example 2: Get Integer Value Using String Key

import java.util.HashMap;

class Main {
  public static void main(String[] args) {
    // create an HashMap
    HashMap<String, Integer> primeNumbers = new HashMap<>();

    // insert entries to the HashMap
    primeNumbers.put("Two", 2);
    primeNumbers.put("Three", 3);
    primeNumbers.put("Five", 5);
    System.out.println("HashMap: " + primeNumbers);

    // get the value
    int value = primeNumbers.get("Three");

    System.out.println("The key Three maps to the value: " + value);
  }
}

Output

HashMap: {Five=5, Two=2, Three=3}
The key Three maps to the value: 3

In the above example, we have used the get() method to get the value 3 using the key Three.