The java.util.Map.equals() method in Java is used to check for equality between two maps. It verifies whether the elements of one map passed as a parameter is equal to the elements of this map or not.
Syntax:
boolean equals(object obj)
Parameters: The method accepts one parameter obj of this map type and refers to the map whose equality is to be checked with this map.
Return Value: The method returns true if the equality holds for both the object map else it returns false.
Below programs illustrate the java.util.Map.equals() method:
Program 1:
// Java code to illustrate the equals() methodimport java.util.*; public class Map_Demo { public static void main(String[] args) { // Creating an empty Map Map<Integer, String> map1 = new HashMap<Integer, String>(); Map<Integer, String> map2 = new HashMap<Integer, String>(); // Mapping string values to int keys map1.put(10, "Geeks"); map1.put(15, "4"); map1.put(20, "Geeks"); map1.put(25, "Welcomes"); map1.put(30, "You"); // Mapping string values to int keys map2.put(10, "Geeks"); map2.put(15, "4"); map2.put(20, "Geeks"); map2.put(25, "Welcomes"); map2.put(30, "You"); // Displaying the Map1 System.out.println("First Map: " + map1); // Displaying the Map2 System.out.println("Second Map: " + map2); // Checking the equality System.out.println("Equality: " + map1.equals(map2)); }} |
Output:
First Map: {20=Geeks, 25=Welcomes, 10=Geeks, 30=You, 15=4}
Second Map: {20=Geeks, 25=Welcomes, 10=Geeks, 30=You, 15=4}
Equality: true
Program 2:
// Java code to illustrate the equals() methodimport java.util.*; public class Map_Demo { public static void main(String[] args) { // Creating an empty Map Map<Integer, String> map1 = new HashMap<Integer, String>(); Map<Integer, String> map2 = new HashMap<Integer, String>(); // Mapping string values to int keys for map1 map1.put(10, "Geeks"); map1.put(15, "four"); map1.put(20, "Geeks"); map1.put(25, "Welcomes"); map1.put(30, "You"); // Mapping string values to int keys for map2 map2.put(10, "Geeks"); map2.put(15, "4"); map2.put(20, "Geeks"); map2.put(25, "Welcomes"); map2.put(30, "You"); // Displaying the map 1 System.out.println("First Map: " + map1); // Displaying the map 2 System.out.println("Second Map: " + map2); // Displaying the equality System.out.println("Equality: " + map1.equals(map2)); }} |
Output:
First Map: {20=Geeks, 25=Welcomes, 10=Geeks, 30=You, 15=four}
Second Map: {20=Geek, 25=Welcomes, 10=Geeks, 30=You, 15=4}
Equality: false
Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Map.html#equals(java.lang.Object)
