Sep 7, 2024 · We can initialize a HashMap using a static block of code: public static Map<String, String> articleMapOne; static { articleMapOne = new HashMap<>(); articleMapOne.put("ar01", "Intro to Map"); articleMapOne.put("ar02", "Some article"); }

With Java 8 or less. You can use static block to initialize a map with some values. Example : public static Map<String,String> test = new HashMap<String, String> static { test.put("test","test"); test.put("test1","test"); } With Java 9 or more. You can use Map.of() method to initialize a map with some values while declaring. Example :

Jun 17, 2024 · Initializing a HashMap can be done in multiple ways, including static blocks, utility methods from the Collections class, and modern approaches provided by Java 8 and Java 9. This article will guide you through these methods with clear examples and explanations.

Nov 19, 2014 · Here is a way to initialize a map using variable declarations when the keys and values are Strings. First declare a two dimensional array of Strings. Use the curly bracket notation to initialize the array, such as

Mar 7, 2025 · In Java, HashMap is part of the Java Collections Framework and is found in the java.util package. It provides the basic implementation of the Map interface in Java. HashMap stores data in (key, value) pairs. Each key is associated with a value, and you can access the value by using the corresponding key.

Jul 1, 2024 · Java allows to initialize a HashMap in different ways and each serves a specific purpose. This Java Collections tutorial explores various initialization techniques for HashMap , including empty maps, pre-populated maps, immutable maps, and collecting Stream items to …

Dec 3, 2020 · This article shows different ways to initialize HashMap in Java. Initialize a HashMap (Standard) Collections.singletonMap; Java 9 Map.of; Java 9 Map.ofEntries; Create a function to return a Map; Static Initializer; Java 8, Stream of SimpleEntry; Conclusion; After initialized a HashMap, the result is either a mutable map or an immutable map:

Mar 7, 2025 · There are multiple ways to Java initialize HashMap, depending on the requirements. You can use the traditional constructor-based approach, anonymous inner classes, static initializers, or Java 8 and 9+ factory methods. Choosing the …

Sep 16, 2024 · Java 17 offers multiple ways to initialize a HashMap directly. Choose the method that best fits your use case, considering factors like mutability, number of entries, and readability. Remember that methods like Map.of() and Map.ofEntries() create immutable maps, while others allow for mutable maps.

Sep 23, 2017 · Following examples demonstrate how to initialize a Java HashMap using standard and inline methods. Why do we need to directly initialize a HashMap?