AbstractMap.SimpleEntry toString() Method in Java with Examples

AbstractMap.SimpleEntry<K, V> is used to maintain a key and a value entry. The value can be changed using the setValue method. This class facilitates the process of building custom map implementations.

toString() method of AbstractMap.SimpleEntry<K, V> returns a String representation of this SimpleEntry map entry. This method returns the string representation of this map entry’s key followed by the equals character (“=”) followed by the string representation of this entry’s value.

Syntax:

public String toString()

Parameters: This method accepts nothing.

Return value: This method returns a String representation of this map entry.

Below programs illustrate toString() method:
Program 1:

// Java program to demonstrate
// AbstractMap.SimpleEntry.toString() method

import java.util.*;
import java.util.AbstractMap.SimpleEntry;

public class GFG {

    @SuppressWarnings({ "unchecked", "rawtypes" })
    public static void main(String[] args)
    {

        // create a ArrayList of Map
        ArrayList<AbstractMap
                      .SimpleEntry<Integer, Integer> >
            arrayList
            = new ArrayList<AbstractMap
                                .SimpleEntry<Integer, Integer> >();

        // add values
        arrayList.add(new AbstractMap.SimpleEntry(0, 123));
        arrayList.add(new AbstractMap.SimpleEntry(1, 130));
        arrayList.add(new AbstractMap.SimpleEntry(2, 994));

        // print keys
        for (int i = 0; i < arrayList.size(); i++) {

            // get map from list
            AbstractMap.SimpleEntry<Integer, Integer>
                map
                = arrayList.get(i);

            // get representation of map using toString()
            String value = map.toString();

            System.out.println(value);
        }
    }
}

Output:

0=123
1=130
2=994

Program 2:

// Java program to demonstrate
// AbstractMap.SimpleEntry.toString() method

import java.util.*;

public class GFG {

    @SuppressWarnings({ "unchecked", "rawtypes" })
    public static void main(String[] args)
    {

        // create a ArrayList of Map
        ArrayList<AbstractMap
                      .SimpleEntry<String, String> >
            arrayList
            = new ArrayList<AbstractMap
                                .SimpleEntry<String, String> >();

        // add values
        arrayList.add(new AbstractMap
                          .SimpleEntry(" 001AB ", " Emp 1"));
        arrayList.add(new AbstractMap
                          .SimpleEntry(" 011AC ", " Emp 2"));
        arrayList.add(new AbstractMap
                          .SimpleEntry(" 111AD ", " Emp 3"));
        arrayList.add(new AbstractMap
                          .SimpleEntry(" 101BE ", " Emp 4"));
        arrayList.add(new AbstractMap
                          .SimpleEntry(" 110CE ", " Emp 5"));

        // print keys
        for (int i = 0; i < arrayList.size(); i++) {

            // get map from list
            AbstractMap.SimpleEntry<String, String>
                map
                = arrayList.get(i);

            // get representation of map using toString()
            String value = map.toString();

            System.out.println(value);
        }
    }
}

Output:

001AB = Emp 1
011AC = Emp 2
111AD = Emp 3
101BE = Emp 4
110CE = Emp 5

References: https://docs.oracle.com/javase/10/docs/api/java/util/AbstractMap.SimpleEntry.html#toString()