{"id":250969,"date":"2024-05-26T11:20:52","date_gmt":"2024-05-26T11:20:52","guid":{"rendered":"https:\/\/namso-gen.co\/blog\/?p=250969"},"modified":"2024-05-26T11:20:52","modified_gmt":"2024-05-26T11:20:52","slug":"have-a-map-return-a-default-value-in-java","status":"publish","type":"post","link":"https:\/\/namso-gen.co\/blog\/have-a-map-return-a-default-value-in-java\/","title":{"rendered":"Have a map return a default value in Java?"},"content":{"rendered":"

Have a map return a default value in Java?<\/p>\n

In Java, the Map interface provides a powerful tool for associating keys with values. Often, we want to retrieve a value from a map based on a given key. However, if the requested key does not exist in the map, Java throws a NullPointerException. To avoid this, we can make use of the Map’s getOrDefault() method, introduced in Java 8, to have the map return a default value instead. <\/p>\n

The getOrDefault() method is pretty straightforward. It takes two parameters: the key to be searched for and the default value to be returned if the key is not found. This way, instead of throwing a NullPointerException, the map will return the default value provided. Let’s see an example to understand it better:<\/p>\n

“`java
\nMap ages = new HashMap<>();
\nages.put(“John”, 25);
\nages.put(“Jane”, 28);<\/p>\n

int peterAge = ages.getOrDefault(“Peter”, 30);
\n\/\/ Since the key “Peter” does not exist, the default value of 30 will be returned
\nSystem.out.println(peterAge);
\n“`<\/p>\n

Output:
\n“`
\n30
\n“`<\/p>\n

In the above code snippet, we have a map called “ages” that associates names with corresponding ages. The map does not contain a key called “Peter,” but we want to retrieve an age for Peter anyway. By using the getOrDefault() method, we specify that if the key “Peter” is not present in the map, the default value of 30 should be returned. As a result, “30” is printed on the console.<\/p>\n

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