How to Clone a Map in Java
Given a map, the task is to clone that map. Following are the 5 different ways to Clone a Map in Java. Example: {1=Geeks, 2=For,… Read More »
Tag Archives: Java-Map-Programs
ArrayList vs. HashMap in Java
ArrayList is a part of collection framework and is present in java.util package. It provides us dynamic arrays in Java. Though, it may be slower… Read More »
How to create a TreeMap in reverse order in Java
By default TreeMap elements in Java are sorted in ascending order of keys. However, we can create the TreeMap in reverse order using Collections.reverseOrder() method… Read More »
How to check if a key exists in a HashMap in Java
Given a HashMap and a key in Java, the task is to check if this key exists in the HashMap or not. Examples: Input: HashMap:… Read More »
Difference between HashMap and HashSet
HashSet is implementation of Set Interface which does not allow duplicate value. The main thing is, objects that are stored in HashSet must override equals()… Read More »
Remove an Entry using value from HashMap while Iterating over it
Given a HashMap and a value in Java, the task is to remove an entry from this HashMap using the value, while iterating over it.… Read More »
Remove an Entry using key from HashMap while Iterating over it
Given a HashMap and a key in Java, the task is to remove an entry from this HashMap using the key, while iterating over it.… Read More »
Flatten a Stream of Map in Java using forEach loop
Given a Stream of Map in Java, the task is to Flatten the Stream using forEach() method. Examples: Input: map = {1=[1, 2], 2=[3, 4,… Read More »
Replace null values with default value in Java Map
Given a Map with null values in it, the task is to replace all the null values with a default value. Examples: Input: map =… Read More »
Program to Convert List to Map in Java
The List is a child interface of Collection. It is an ordered collection of objects in which duplicate values can be stored. Since List preserves… Read More »
Sort elements by frequency | Set 5 (using Java Map)
Given an integer array, sort the array according to the frequency of elements in decreasing order, if frequency of two elements are same then sort… Read More »
Using TreeMap to sort User-defined Objects in Java
Given example shows how to sort user defined objects TreeMap, you can sort the keys based on the logic provided inside the method. Given a… Read More »
Program to Convert HashMap to TreeMap in Java
HashMap is a part of Java’s collection since Java 1.2. It provides the basic implementation of Map interface of Java which stores the data in… Read More »
Traverse through a HashMap in Java
HashMap is a part of the java collections framework. It internally uses hashing technique. This post contains different ways of traversing through a HashMap, which… Read More »
Initialize HashMap in Java
HashMap is a part of java.util package.HashMap extends an abstract class AbstractMap which also provides an incomplete implementation of Map interface. It stores the data… Read More »
