Create a Java program named StringTest.java and write a main method that contains expressions that combine various types using the + operator. For example, what happens when you add " a String and a char? (a) Does it perform character addition or string concatenation? (b) How can you determine the type of the result?

Add a static method, public static void changeLetter (StringBuilder sb, char letter) Convert all occurrences of the letter variable in the StringBuilder to upper case. Write in java and use test case example as reference.

How do I create a code that has a public static method named replaceFirst that takes in a String s and a char c as arguments. The method will return a modified String replacing the first character with the one that was passed in. (Do not print out the String) Java

3. Create a program for Smalltown Regional Airport Flights that accepts either an  integer flight number or string airport code from the options in Figure 8-33. Pass the user’s entry to one of two overloaded GetFlightInfo() methods, and then display a  returned string with all the flight details. The method version that accepts an integer looks up the airport code, name, and time of flight; the version that accepts a string description looks up the flight number, airport name, and time. The methods return an appropriate message if the flight is not found.  Farrell, Joyce. Microsoft Visual C#: An Introduction to Object-Oriented Programming (MindTap Course List) (p. 347). Cengage Learning. Kindle Edition.

Need help with this java problem. Some Websites impose certain rules for passwords.Write a method that checks whether a string is a valid password.  The method must takes a password as a parameter and return a boolean value.  If the password is valid, returns true, otherwise, return false. Suppose the password rules are as follows:- A password must have at least eight characters.- A password must contain only letters and digits.- A password must contain at least two digits. Please make sure you write a comment line to document what your method does. Write a program that prompts the user to enter a password, then call the method that checks the password, and displays "Valid Password" if the rulesare followed, or Invalid Password otherwise.  The main program must allow the user to check multiple passwords.  It should ask the user "Do you want to continue checking anther password (y/n)?"

In this assignment you will demonstrate your knowledge of debugging by fixing the errors you find in the program below. Fix the code, and paste it in this document, along with the list of the problems you fixed.This example allows the user to display the string for the day of the week. For example, if the user passed the integer 1, the method will return the string Sunday. If the user passed the integer 2, the method will return Monday. This code has both syntax errors and logic errors. Hint: There are two logic errors to find and fix (in addition to the syntax errors).Inport daysAndDates.DaysOfWeek;public class TestDaysOfWeek {public static void main(String[] args) {System.out.println("Days Of week: ");for (int i = 0;i < 8;i++) {System.out.println("Number: " + i + "\tDay Of Week: " + DaysOfWeek.DayOfWeekStr(i) )}}}package daysAndDatespublic class DaysOfWeek {public static String DayOfWeekStr(int NumberOfDay) {String dayStr = ""switch (NumberOfDay) {case 1:dayStr =…

Need help with 8,9, and 10 if possible. Java Coding

Please write a java code using the photo below. The second photo is the output of my program that I am writing

I need to create a code for tic tac toe in java where you play against a computer. I need the board to be in an array of char

// Program displays some facts about a stringpublic class DebugSeven3{public static void main(String[] args){ String quote ="Honesty is the first chapter in the book of wisdom. - Thomas Jefferson"; System.out.println("index.of('f') is: " + indexOf('f'));System.out.println("index.of('x') is: " + indexOf('x'));System.out.println("char.At(5) is: " + charAt(5));System.out.println("endsWith(\"daughter\") is: " + quote.endswith("daughter"));System.out.println("endsWith(\"son\") is: " + quote.endswith("son"));System.out.println("replace('e', '*') is: " + quote.replace('e', 'M'));}}