Java

In the vast landscape of programming languages, Python and Java have emerged as titans, offering robust solutions for a wide range of applications. When it comes to performance, developers often find themselves pondering which language reigns supreme. In this blog post, we will delve into the world of Python and Java, exploring their performance characteristics, strengths, and weaknesses, and ultimately helping you make an informed choice for your next project....

Learning Java in one day is not a realistic goal, as Java is a complex programming language that requires time and practice to master. However, here are some tips to get you started: Start with the basics: Before diving into complex topics, learn the basics of Java, such as variables, data types, control structures, and object-oriented programming principles. Watch tutorials and read documentation: There are many resources available online that can help you learn Java quickly....

The challenge Reverse Number is a number which is the same when reversed. For example, the first 20 Reverse Numbers are: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44, 55, 66, 77, 88, 99, 101 Task You need to return the nth reverse number. (Assume that reverse numbers start from 0 as shown in the example.) Notes 1 < n <= 100000000000 The solution in Java Option 1:...

The challenge Write a function called sumIntervals/sum_intervals() that accepts an array of intervals, and returns the sum of all the interval lengths. Overlapping intervals should only be counted once. Intervals Intervals are represented by a pair of integers in the form of an array. The first value of the interval will always be less than the second value. Interval example: [1, 5] is an interval from 1 to 5. The length of this interval is 4....

If you need to compile multiple Java files using a single command, then you can do the following. First, it’s good to learn how to compile a Java file. How to Compile a Java File Let’s take the following Java code: class HelloWorld { public static void main(String[] args) { System.out.println("Hello World"); } } To compile this, we simply do the following: javac HelloWorld.java Then when we need to run it, we do:...

If you need to convert JSON to a Java Object, then you can do one of the following: Option 1 – Using Gson import com.google.gson.Gson; public class SimpleTesting { public static void main(String[] args) throws InterruptedException { String json = """ { "firstName" : "Jane", "lastName" : "Doe", "dateOfBirth" : "1973-04-29", "address" : "81 Hype", "city" : "New York", "contact" : "0123456789" } """; Student data = new Gson().fromJson(json, Student.class); System....

If you need to calculate the powers of Integers in Java, then you can do one of the following: Option 1 – Using for loops public class Power { public static void main(String args[]){ int number = 5; int power = 3; int result = calculatePower(number,power); System.out.println(number+"^"+power+"="+result); } static int calculatePower(int num, int power){ int answer = 1; if (num > 0 && power==0){ return answer; } else if(num == 0 && power>=1){ return 0; } else{ for(int i = 1; i<= power; i++) answer = answer*num; return answer; } } } Option 2 – Using Recursion public class Power { public static void main(String args[]){ int number = 3; int power = 3; int result = CalculatePower(number,power); System....

If you need to get today’s date in Java, then you can do one of the following: Option 1 – Using LocalDate import java.time.LocalDate; public class GetTodayDate { public static void main(String[] args) { LocalDate todaysDate = LocalDate.now(); System.out.println(todaysDate); } } Option 2 – Using Calendar and SimpleDateFormat import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; public class GetTodayDate { public static void main(String[] args) { SimpleDateFormat dtf = new SimpleDateFormat("yyyy/MM/dd"); Calendar calendar = Calendar....

Let’s say you have a Java project as follows: package ms.ao.something; public class MyProject { public static void main(String...args) throws Exception { System.out.println("Hello world!"); } } Now you want to build this and make it a self contained executable Jar. If you do a mvn clean install or mvn clean package, and try and run it as follows: java -jar target/my-java-1.0-SNAPSHOT.jar You will get the following error: no main manifest attribute, in target/my-java-1....

If you need to read a file line by line in Java, then you can use one of the following three (3) options. Option 1 You can use the FileReader and BufferedReader packages as follows: File file = new File("./your/file.txt"); try (FileReader fr = new FileReader(file); BufferedReader br = new BufferedReader(fr);) { String line; while ((line = br.readLine()) != null) { System.out.println(line); } } catch (IOException e) { e.printStackTrace(); } Option 2 You can also read the lines using Files and Paths as follows:...