Arrays and lists are fundamental data structures in Java that allow you to store collections of elements: Arrays: In Java, an array is a fixed-size, ordered collection of elements of the same type. It provides a contiguous block of memory to store the elements and allows direct access to each element using an index. Arrays…
Read More Convert an Array to a List in JavaWhen working with Java programming, it is often essential to determine whether a given string represents a numeric value. This task is crucial for a variety of scenarios, such as validating user input, performing calculations, or processing data. By accurately identifying numeric strings, you can ensure the correctness and integrity of your application’s logic. The…
Read More Java: Check if String is NumericAccessing elements from an ArrayList is a fundamental operation in Java programming. ArrayLists are commonly used to store and manage collections of objects dynamically. Being able to retrieve elements enables you to work with the data stored within the ArrayList effectively. Whether you need to display elements, perform calculations, or manipulate the data in any…
Read More How to Get an Element from an ArrayList in Java?The purpose of this tutorial is to provide a comprehensive guide on updating keys in a HashMap in Java. As Java developers, we often encounter situations where we need to modify the keys associated with certain values in a HashMap. This tutorial aims to equip you with various methods and techniques to update keys efficiently…
Read More Java: Updating Keys in a HashMapWhen working with strings in Java, it is essential to check if a string is null or empty. A null string refers to the absence of any value, while an empty string is a string with zero characters. Failing to handle null or empty strings appropriately can lead to unexpected errors and undesired behavior in…
Read More Check if String is Null or Empty in JavaFinding the maximum and minimum values in an array is a common requirement in various programming scenarios. It allows you to extract key insights from your data, such as identifying the highest and lowest values, or determining the range of values present. This knowledge can be utilized in numerous applications, including statistical analysis, data processing,…
Read More Finding Max and Min Values in a Java ArrayReversing a string is a common task in Java programming, and there are several ways to accomplish this. In this tutorial, we’ll explore four different methods for reversing a string in Java, using the StringBuilder class, the for loop, recursion, and a character array. We’ll provide examples of each method and explain how they work.…
Read More Reverse a String in JavaWorking with strings is a fundamental aspect of programming, and Java provides a rich set of tools and methods for manipulating strings. One common task when working with strings is to remove whitespace characters such as spaces, tabs, and newlines. There are several ways to accomplish this in Java, including using the replaceAll() method from…
Read More Removing Whitespaces in Java StringsConvert char to String in Java using the String.valueOf() method There is a valueOf() static method in the String class that returns the String representation of its argument, which can be a char or any other data type. public class Test { public static void main(String[] args) { char ch = ‘a’; String str =…
Read More Convert Char to String in JavadataType[] arr; Where: int[] intArray = new int[5]; String[] arr = new String[3]; arr[0] = “value 1”; arr[1] = “value 2”; arr[2] = “value 3”;
Read More How to Declare an Array in Java?class PrintArrayElementsExample { public static void main(String[] args) { int[] arr1 = {1, 7, 9, 5, 2, 8, 3}; String[] arr2 = {“Megan”, “Tom”, “Melissa”, “John”, “Steve”}; // print elements of the arr1 System.out.println(Arrays.toString(arr1)); // print elements of the arr2 System.out.println(Arrays.toString(arr2)); } } Output: [1, 7, 9, 5, 2, 8, 3] [Megan, Tom, Melissa, John,…
Read More Print Array Elements in Javapublic class SplitString { public static void main(String[] args) { String names = “Tom,Steve,John,Megan,Melissa”; // split string String[] arr = names.split(“,”); // print the size of the array System.out.println(arr.length); // print the elements Stream.of(arr).forEach(System.out::println); } } Output: 5 Tom Steve John Megan Melissa If you need a list, instead of an array, use the…
Read More Split a comma-separated String in JavaWant to learn how to merge two ArrayLists in Java? In this post, we will cover the following ways: Using the List.addAll() method Using the Java 8 Streams Using the ListUtils.union() method Merge two ArrayLists in Java using the List.addAll() method There is addAll() method from the List interface that appends all of the elements in…
Read More How to merge two ArrayLists in Java?In this post, you will learn how to Serialize and Deserialize an ArrayList in Java using the FileOutputStream and FileInputStream classes. How to Serialize an ArrayList in Java? Serialization is the process of changing the state of an object into a byte stream. For example, we use it to write some Java objects into a file. In…
Read More Serialize and Deserialize an ArrayList in JavaNeed to remove a character from String in Java? You can do that by converting the String to a StringBuilder class and using the deleteCharAt() method that removes the character at a specified position. Example class Test { public static void main(String[] args) { String str = “Learn Java”; str = new StringBuilder(str).deleteCharAt(5).toString(); System.out.println(str); } }…
Read More Remove a Character from String in Java