How to Convert an Array to a Map in Java

Converting an Array to a Map in Java

In Java, converting an array to a map can be a useful operation when you need to associate values with specific keys. This process involves iterating through the array and mapping each element to a corresponding key in the map. Let’s explore a simple example with working code:

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import java.util.HashMap;
import java.util.Map;

public class ArrayToMapConverter {

    public static void main(String[] args) {
        // Sample array
        String[] array = {"one", "two", "three", "four", "five"};

        // Convert array to map
        Map<Integer, String> resultMap = convertArrayToMap(array);

        // Print the resulting map
        System.out.println("Array to Map: " + resultMap);
    }

    private static Map<Integer, String> convertArrayToMap(String[] array) {
        Map<Integer, String> map = new HashMap<>();

        // Iterate through the array
        for (int i = 0; i < array.length; i++) {
            // Map each element to its index
            map.put(i, array[i]);
        }

        return map;
    }
}

Explanation:

1. We start by importing the necessary Java classes for handling maps (HashMap and Map).
2. In the ArrayToMapConverter class, we define a main method where we create a sample string array.
3. We then call the convertArrayToMap method to convert the array to a map and store the result in resultMap.
4. The convertArrayToMap method takes a string array as a parameter and initializes an empty HashMap.
5. We iterate through the array using a simple for loop, mapping each element to its corresponding index in the map.
6. Finally, the resulting map is returned.

This straightforward example demonstrates how to convert an array to a map in Java, providing a clear foundation for more complex scenarios.