In what circumstances, compiler will supply a default
constructor for a class?
Answer Posted / ranganathkini
If no constructors are explicitly defined for the class,
Java supplies a default no-arg constructor which does
nothing more than initialize the fields of the class to
their default value.
Is This Answer Correct ? | 0 Yes | 0 No |
Post New Answer View All Answers
Describe 2 different ways to concatenate two strings.
What is an 8 bit word?
Can we have more than one package statement in the source file?
List primitive java types?
Which sorting is used in arrays sort in java?
What is meant by the value of a variable?
Can finally block be used without a catch?
Can we define a package statement after the import statement in java?
How will you call an Applet using Java Script Function?
What is the generic function?
Why put method is used?
Is hashset sorted in java?
What does java ide mean?
The following program reads data (details of students) from a file named students.txt and converts it into e-mail addresses. The results are written to a file named studentemail.txt. students.txt consists of a number of lines, each containing the data of a student in colon delimited format: Last Name:First Name:Student Number Each input record is converted to an e-mail address and written to studentemail.txt in the following format: the first character of the last name + the first character of the first name + the last four digits of the student number + “@myunisa.ac.za” import java.io.*; public class EmailConverter { public static void main(String[] args) throws IOException { BufferedReader input = new BufferedReader(new FileReader ("students.txt")); PrintWriter output = new PrintWriter(new FileWriter ("studentemail.txt")); String line = input.readLine(); while (line != null) { // Extract the information for each student String[] items = line.split(":"); // Generate the email address String email = "" + items[0].charAt(0) + items[1].charAt(0) + items[2].substring(4,8) + "@myunisa.ac.za"; email = email.toLowerCase(); // Output output.println(email); line = input.readLine(); } input.close(); output.close(); } } Rewrite the class so that it handles possible errors that may occur. In particular, it should do the following: • It should catch at least three appropriate exceptions that might occur, and display suitable messages. • At this stage, the program will not run correctly if there is an empty line in the input file. Change the program so that if an empty line is encountered, an exception is thrown and the empty line is ignored. This exception should be handled with the display of a suitable error message. • Before the e-mail address is added to the output file, check if the student number has 8 digits. If not, throw an InvalidFormatException (which the program should not handle itself)
Can arraylist hold different types java?