Basic Java Program for Beginners

Author: J-B-Mugundh

Bug3524.java

@@ -0,0 +1,11 @@
+import java.util.Scanner;
+public class Bug3524 {
+ public static void main(String[] param) {
+ System.out.println("2021503524 - Mugundh J B - 09/09/23 - 2.20 pm");
+ Scanner in = new Scanner(System.in);
+ System.out.println("Hello. Please type your name:");
+ String name = in.nextLine();
+ System.out.println("Hello "+name);
+ System.out.println ("Have a, nice day!");
+ }
+}

Temp3524.java

@@ -0,0 +1,14 @@
+import java.util.Scanner;
+import java.text.DecimalFormat;
+public class Temp3524 {
+ public static void main(String[] args){
+ Scanner in = new Scanner(System.in);
+ System.out.println("2021503524 - Mugundh J B - 09/09/23 - 2.40 pm");
+ System.out.print("Enter temperature in Fahrenheit: ");
+ float fah = in.nextFloat();
+ float c = (fah - 32) * 5 / 9;
+ DecimalFormat df = new DecimalFormat("0.00"); // Used to format the decimal value in form of pattern
+ System.out.printf("Fahrenheit temperature " + df.format(fah) +
+ " is the same \nas " + df.format(c) + " degrees Celsius.");
+ }
+}

Verbalize3524.java

@@ -0,0 +1,40 @@
+import java.time.LocalDate;
+import java.time.LocalTime;
+import java.util.Scanner;
+public class Verbalize3524{
+ // Arrays to store the verbal representations of units and tens
+ private static final String[] units = {
+ "", "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine", "Ten",
+ "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen", "Sixteen", "Seventeen", "Eighteen", "Nineteen"
+ };
+ private static final String[] tens = {
+ "", "", "Twenty", "Thirty", "Forty", "Fifty", "Sixty", "Seventy", "Eighty", "Ninety"
+ };
+ public static void main(String[] args) {
+ System.out.println("2021503524 - Mugundh J B");
+ System.out.println("Date: " + LocalDate.now() + " Time: " + LocalTime.now());
+ Scanner scanner = new Scanner(System.in);
+ System.out.print("Enter a number between 1 and 9999: ");
+ int number = scanner.nextInt();
+ // Check for invalid input
+ while (number < 1 || number > 9999) {
+ System.out.print("Invalid input. Please enter a number between 1 and 9999: ");
+ number = scanner.nextInt();
+ }
+ // Convert the number to its verbal representation
+ String verbalized = convertToWords(number);
+ System.out.printf("Verbalized form:\n" + verbalized);
+ }
+ // Convert a number to its verbal representation
+ public static String convertToWords(int number) {
+ if (number < 20) {
+ return units[number]; // Directly use the units array
+ } else if (number < 100) {
+ return tens[number / 10] + " " + units[number % 10]; // Combine tens and units
+ } else if (number < 1000) {
+ return units[number / 100] + " Hundred and " + convertToWords(number % 100); // Handling hundreds by recursion
+ } else {
+ return units[number / 1000] + " Thousand and " + convertToWords(number % 1000); // Handling thousands by recursion
+ }
+ }
+}

dataType3524.java

@@ -0,0 +1,19 @@
+public class dataType3524 {
+// // Integer data types
+// byte byteValue = 127; // Correct
+// // byte byteValue = 128; // Incorrect: Value exceeds the valid range (-128 to 127)
+// long longValue = 9223372036854775807; // Incorrect, require L at the end
+// long longValue = 9223372036854775807L; // Correct
+// long longValue = 9223372036854775807; // Incorrect, require L at the end
+// long longValue = 9223372036854775808L; // Incorrect: Value exceeds the valid range
+// // Floating-point data types
+// float floatValue = 3.14f; // Correct
+// float floatValue = 3.14; // Incorrect: Floating-point literals need 'f' or 'F' suffix
+// // Boolean data type
+// double doubleValue = 3.14159; // Correct
+// // Character data type
+// char charValue = 'A'; // Correct
+// char charValue = "A"; // Incorrect: Use single quotes for characters
+// boolean booleanValue = true; // Correct
+// boolean booleanValue = 0; // Incorrect: Use 'true' or 'false' for boolean values
+}

dateTime3524.java

@@ -0,0 +1,17 @@
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+
+public class dateTime3524 {
+ public static void main(String[] args) {
+ System.out.println("2021503524 - Mugundh J B \n");
+ LocalDateTime current = LocalDateTime.now(); //"LocalDateTime" is the class
+ //"now()" is a method, represent the current date and time
+ DateTimeFormatter dateformat = DateTimeFormatter.ofPattern("yyyy-MM-dd");
+ DateTimeFormatter timeformat = DateTimeFormatter.ofPattern("HH:mm:ss");
+ // ofPattern() is used to format the date in a particular pattern
+ String formattedDate = current.format(dateformat);
+ System.out.print("Date: " + formattedDate);
+ String formattedTime = current.format(timeformat);
+ System.out.println(" Time: " + formattedTime);
+ }
+}

digitalWatch3524.java

@@ -0,0 +1,58 @@
+import java.time.LocalDate;
+import java.time.LocalTime;
+import java.util.Scanner;
+public class digitalWatch3524 {
+ public static void main(String[] args) {
+ System.out.println("2021503524 - Mugundh J B");
+ System.out.println("Date: " + LocalDate.now() + " Time: " + LocalTime.now());
+ Scanner scanner = new Scanner(System.in);
+ // Prompt the user for input
+ System.out.print("Input day (Mon, Tue, Wed, Thu, Fri, Sat, Sun): ");
+ String day = scanner.nextLine();
+ System.out.print("Input hour (24-hour): ");
+ int hour = scanner.nextInt();
+ System.out.print("Input minute: ");
+ int minute = scanner.nextInt();
+ System.out.print("Input second: ");
+ int second = scanner.nextInt();
+ // Validating day input
+ if (!isValidDay(day)) {
+ System.out.println("Invalid day input!");
+ } else if (hour < 0 || hour > 23 || minute < 0 || minute > 59 || second < 0 || second > 59) {
+ System.out.println("Invalid time input!");
+ } else {
+ // Advancing time by one second
+ second++;
+ if (second == 60) {
+ second = 0;
+ minute++;
+ if (minute == 60) {
+ minute = 0;
+ hour++;
+ if (hour == 24) {
+ hour = 0;
+ day = getNextDay(day);
+ }
+ }
+ }
+ // Displaying the new time
+ System.out.println("New time: " + day + " " + hour + " " + minute + " " + second);
+ }
+ }
+ // Checking if the given day is valid
+ public static boolean isValidDay(String day) {
+ return day.equals("Mon") || day.equals("Tue") || day.equals("Wed") ||
+ day.equals("Thu") || day.equals("Fri") || day.equals("Sat") || day.equals("Sun");
+ }
+ // Getting the next day
+ public static String getNextDay(String day) {
+ if (day.equals("Sun")) return "Mon";
+ if (day.equals("Mon")) return "Tue";
+ if (day.equals("Tue")) return "Wed";
+ if (day.equals("Wed")) return "Thu";
+ if (day.equals("Thu")) return "Fri";
+ if (day.equals("Fri")) return "Sat";
+ if (day.equals("Sat")) return "Sun";
+ return "";
+ }
+}

finalVelocity3524.java

@@ -0,0 +1,21 @@
+import java.util.Scanner;
+public class finalVelocity3524 {
+ public static void main(String[] args){
+ Scanner in = new Scanner(System.in);
+ System.out.println("2021503524 - Mugundh J B - 09/09/23 - 3 pm");
+
+ System.out.print("Enter the starting speed: ");
+ float u = in.nextFloat();
+ System.out.print("Enter the acceleration: ");
+ float a = in.nextFloat();
+ System.out.print("Enter the time: ");
+ float t = in.nextFloat();
+
+ float d = (float) (u * t + (0.5 * a * t * t)); // Formula to calc displacement
+ System.out.printf("The displacement is %.2f", d);
+
+ float v = u + a * t; // Formula to calc final velocity
+ System.out.printf("\nThe final velocity is %.2f", v);
+
+ }
+}

headsTails3524.java

@@ -0,0 +1,39 @@
+import java.time.LocalDate;
+import java.time.LocalTime;
+import java.util.*;
+
+public class headsTails3524 {
+ public static void main(String[] args) {
+ System.out.println("2021503524 - Mugundh J B");
+ System.out.println("Date: " + LocalDate.now() + " Time: " + LocalTime.now());
+
+ // Create a random number generator
+ Random rand = new Random();
+
+ // Generate a random number (0 or 1)
+ int num = rand.nextInt(2);
+
+ // Create a Scanner to read user input
+ Scanner in = new Scanner(System.in);
+
+ // Prompt the user for their choice
+ System.out.print("Enter your choice (h / H / t / T): ");
+ char choice = in.next().charAt(0);
+
+ // Validate user's choice
+ while (choice != 'h' && choice != 'H' && choice != 't' && choice != 'T') {
+ System.out.printf("Invalid choice. Enter your choice (h / H / t / T): ");
+ choice = in.next().charAt(0);
+ }
+
+ // Display the random value generated
+ System.out.printf("Random value = %d\n", num);
+
+ // Check if the user won or lost based on their choice and the random value
+ if (((choice == 'h' || choice == 'H') && num == 1) || ((choice == 't' || choice == 'T') && num == 0))
+ System.out.print("You won!");
+ else
+ System.out.print("You lose!");
+
+ }
+}

helloWorld3524.java

@@ -0,0 +1,13 @@
+
+import java.time.LocalDate;
+import java.time.LocalTime;
+
+public class helloWorld3524 {
+ public static void main(String[] a) {
+ System.out.println("2021503524 - Mugundh J B");
+ System.out.printf("Date: " + LocalDate.now() + " Time: " + LocalTime.now());
+ System.out.print("\nHello, ");
+ System.out.print(a[0]);
+ System.out.println("\nGood morning! ");
+ }
+}

monthDays3524.java

@@ -0,0 +1,42 @@
+import java.time.LocalDate;
+import java.time.LocalTime;
+import java.util.Scanner;
+
+public class monthDays3524 {
+ public static void main(String[] args) {
+ System.out.println("2021503524 - Mugundh J B");
+ System.out.println("Date: " + LocalDate.now() + " Time: " + LocalTime.now());
+ Scanner scanner = new Scanner(System.in);
+
+ System.out.print("Enter the year: ");
+ int year = scanner.nextInt(); // Getting the year as input
+
+ while (year < 1000 || year > 9999) { // Checking if the entered year is valid
+ System.out.printf("Invalid input for the year!\nEnter the year again: ");
+ year = scanner.nextInt(); // Getting input again if input is invalid
+ }
+ System.out.print("Enter the month (1 to 12): ");
+ int month = scanner.nextInt(); // Getting the month as input
+
+ int daysInMonth = 0; // Variable to store no of days in that month
+ switch(month){
+ case 1: case 3: case 5: case 7: case 8: case 10: case 12:
+ daysInMonth = 31;
+ break;
+ case 4: case 6: case 9: case 11:
+ daysInMonth = 30;
+ break;
+ case 2:
+ if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)) {
+ daysInMonth = 29; // Leap year
+ } else {
+ daysInMonth = 28; // Non-leap year
+ }
+ break;
+ default:
+ System.out.println("Invalid month!");
+ return;
+ }
+ System.out.printf("Number of days in %d th month: %d", month, daysInMonth);
+ }
+}