I have learn that every function in java is treated as a normal function including main() except that execution of a program starts here. I tried to overload it.
But I am getting error while doing so via String type array as an argument of main.
class Hello
{
public static void main()
{
System.out.println("Hello");
}
public static void main(String... s)
{
System.out.println("main from Hello");
[Code] .....
One interviewer has asked me one question that why main() method has argument "String[] arg".What is reason behind this ??I am unable to explain it because i never think about it ..
View Replies View RelatedI have the following code in which I am looping through the rows of one array (composed of Strings) and copying it to another array. I am using .clone() to achieve this and it seems work as it changes the memory location of the rows themselves. I did notice that the String objects are still pointing to the same location in memory in both arrays but I won't worry about that for now, at the moment I just want to understand why the array I am cloning is not successfully assigning to the other array.
This is the incorrect line: ar[r] = maze[r].clone();
My code:
private String[][] maze = {{"*","*","*"," ","*","*","*","*","*","*"},
{"*"," ", "*"," "," "," ","*"," ","*","*"},
{"*"," ","*","*","*"," ","*"," ","*","*"},
{"*"," "," "," "," "," "," "," "," ","*"},
{"*","*","*","*","*"," ","*","*","*","*"},
{"*","*","*","*","*"," ","*","*","*","*"}};
//private String[][] mazeCopy = copyMaze(new String[6][10]);
private <T> T[][] copyMaze(T[][] ar){
for (int r = 0; r < ar.length; r++){
ar[r] = maze[r].clone();
}
return ar;
}
My compiler says: Required: T[]. Found: java.lang.String[]
Since ar[r] is an array and .clone() also returns an array why is this line incorrect.
I am using Oracle Java 8 in Eclipse working on both Ubuntu and OSX. I have this code:
Java Code:
private static String getConfigDir(){
Path configDir = Paths.get(homeDir(), homeConfig(), appName());
return configDir.toString();
[code]...
But for the method get() of Paths, I get this error in eclipse.The method get(String, String[]) in the type Paths is not applicable for the argument..Yet on the Oracle documentation site, it uses a similar example:
Path p5 = Paths.get(System.getProperty("user.home"),"logs", "foo.log");
I've a problem in encoding a URL string.
I know to encode a string we use,
URLEncoder.encode(stringname,"UTF-8");
But when I use this I'm getting an error telling that the encode method will accept only 1 String argument.
I am trying to pass an object of type Product p to my editProduct method, however trying to call p.getName(); doesn't work and throws a NullPointerException. The same kind of thing works for my displayRecord method (in a different class) and I can call .getName() on Product p, also passed as an argument to that method. Below is my editProduct class. The NullPointerExcepion is being thrown at line 61 (i.e., nameField.setText(p.getName());).
I don't know if I explained right, so here's a line thing of how the classes relate:
Search >>>(field.getText())>>> displayRecord(Product p) >>>editProduct(p)>>> EditProduct
And as a side note: adding the line p = new Product(); fixes it and successfully runs the class (including the Save and Quit parts) but obviously I want it to specifically refer to the Product I pass to the method.
Java Code:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.util.ArrayList;
import javax.swing.BorderFactory;
[Code] ....
I'm asking a question because I don't understand how Product p could possibly be null, because the argument is passed through my DisplayRecord class, which also takes a Product p argument and works. In that class, I have declared Product prod = p; and prod is what I am passing to editProduct.
I have a String repersentaion of some Object.I want that object convert back into some class type how can I do this?
View Replies View RelatedFor some reason when I try to run the program it gives me an "editor does not contain a main type" launch error.
/*
* A program that plays and scores a round of the game Poker Dice. In this game, five dice are rolled. The player is allowed to select a number of those five dice to re-roll. The dice are re-rolled and then scored as if they were a poker hand. The following hands MUST be scored in this assignment:
* * High card
* * One Pair
* * Two Pair
* * Three of a Kind
* * Full House
* * Four of a Kind
* * Five of a Kind
* For extra credit, you may also implement:
* * Straight
*/
import java.util.Scanner;
public class Project10 {
public static void main(String[] args) {
Scanner inScanner = new Scanner(System.in);
int[] dice = new int[5];
resetDice(dice);
System.out.print("Your current dice: + dice");
[code]....
I'm trying to run a simple code which is to just print out "Hello World", but whenever I run it, a message appears that reads: "Select a way to run Project_1(Which is the Java Project)"
The selections for it are: Java Applet and Java Application.Whenever I click Java Applet it reads: Selection does not contain an applet.When I click Java Application: Selection does not contain a main type.Here is the code which I believe is correct:
package packag_1;
public class Num_1 {
public static void main(String args){
System.out.println("Hello World");
}
}
I'm trying to make a simple Caesar cipher that takes in a String as the first argument and a integer shift as the second argument. Namely, there appears to be a problem with the loop and how I have declared the array - I want the converted characters to be put into a new array called newCharacterArray, converted back to a String and displayed in the command prompt window.
public class Caesar {
public static void main(String inString, int k) {
System.out.println("String: " + inString);
char inStringArray[] = inString.toCharArray();
[code]....
Can we pass array as a cmd line argument as follows ?
>java TestRun file[], number
if yes, in the main(), how do we capture this array ?
public static void main(String [] args){
String [] files = args1 ;
// or will it be String [] files = args1[];
}
class Passenger{
String name;
int age;
char gender;
int weight;
public Passenger(){
[Code] ....
This is showing error.....error it gives isthat it cannot change from string type to passenger type......... How to do it??????
Is this possible in Java?
public void doSomething(int[4] year){
}
What I am trying to do is to get the person who is using the method to send a year in the format 1998 and so on.
What would be the best way to accomplish this?
how to search array elements present or not using command line argument in java
View Replies View RelatedThe objective of the code is to add new records based on existing records with a partial change to the key. I'm getting "type of the expression must be an array type but it resolved to DstidArray" on dsTidRecTbl[i]
String stMajor = request.getParameter("stMajorVersion");
String stMinor = request.getParameter("stMinorVersion");
String stPatch = request.getParameter("stPatchVersion");
StringBuffer stKeySB = new StringBuffer(stMajor+stMinor+stPatch);
String stKey = new String(stKeySB.toString());
DstidArray dsTidRecTbl = new DstidArray(stKey);
request.setAttribute("dsTidRecTbl", dsTidRecTbl);
[code]....
I am writing a code where in the first method the question will ask whats your favorite website. for example www.javaprogrammingforums.com...when it outputs it will read just "javaprogrammingforums" without the www. and the .com.
Because the program will ask a series of questions in the main, I would like website question to be returned to the main. Here is my code, and what can I do?
import java.util.Scanner;
public class chapter3 {
public static String website(Scanner kb) {
String website;
System.out.println("What is your favorite website?");
website = kb.next();
[Code] ......
The following code is located in my main class called InjectionFix. I have another class where I need to call or initiate the string in the code below. How can I achieve this. I tried to create an Object of the class but I cant do this because my other class doesnt contain a main method.How can I get the other class to initiate the code below which is loacted in my main class.
public static String escapeDN(String name) {
StringBuilder sb = new StringBuilder();
// space or # character at the beginning of a string
if ((name.length() > 0) &&
((name.charAt(0) == ' ') ||
(name.charAt(0) == '#'))) {
[Code] .....
I want to return values from arrays to the main and the problem is i cant use my variables from my constructor, I use new variables in my functions and i know this is no good, when I used the variables from the constructor in my function. I have a compilations errors,also i want to create un object in main and with this object i want to call the functions.
Java Code:
package javaapplication4;
import java.util.Scanner;
public class JavaApplication4 {
public static int[] MyInt;
public static double[] MyDouble;
public static String[] MyString;
public static char[] MyChar;
[Code] .....
The code is working when i run it and i have the right result in my screen but i know this is all wrong with the variables.
why my session not type casting into String? I'm placing that code below where problem arised.
HttpSession hs1=request.getSession(false);
out.println("hi");
String t1=(String)hs1.getAttribute("name");
out.println("hi "+t1);
in my above code first "hi" is printed successfully but next statement arises type cast exception.
I have to use a long primitive type for the input of a credit card number and ID the credit card by using the first number of the input; however, the only way I know for that is to use charAt, which is used for a String. Is there a way to convert long to String, or am I missing a better solution? (There's no code because I'm still doing the pseudocode).
View Replies View RelatedAm doing mapreduce in java for hadoop. The below code is for Reducer. i get a problem with the TryParseint. What is this error and how to rectify it?
Error : The method TryParseInt(String) is undefined for the type MaxPubYearReducer
import java.io.IOException;
import java.util.*;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.conf.*;
import org.apache.hadoop.io.*;
[Code] ....
Attached image(s)
I believe I am on the right track but when I run the program I get an error that the class that I can't call on the method. I need to have what is selected in the JCheckBoxes added to the toppings array and I can't get that done what so ever.
Java Code:
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
public class PizzaOrderListener
{
public static void main(String[] args) {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
[Code] ....
I have created an enumerated data type that represents months. In my program I have asked the user for the month. I hold the month entered by user into a string variable. From that string variable I'm trying to display the month using my enumerated data type. I know I can use if statements, but is there another simple way to do it?
import java.util.Scanner;
public class demo {
//Enum class called month that has constants in it representing months
enum month{january,february,march,april,may,june, july,august,september,
october,november, december};
[Code] ....
I'm trying to return an array back to main. The array returned to main should contain the reversed random numbers array. I believe I have the array correctly reversed within the 'reverseArray' method. I'm trying to send this array back to main, but it appears to contain empty data (a bunch of zeros).
Java Code:
class ArrToMain {
public static void main(String[] args) {
final int NUMBER_OF_ELEMENTS = 1000;
double[] numbers = new double [NUMBER_OF_ELEMENTS];
//Invoke initialize method
initialize(numbers);
[Code] ......
Here I have an enum class
public enum Money{
ONE_PENNY(1),
TWO_PENCE(2),
FIVE_PENCE(5),
TEN_PENCE(10),
TWENTY_PENCE(20),
FIFTY_PENCE(50),
ONE_POUND(100),
TWO_POUNDS(200);
private int coin;
Money(int c) {
coin = c;
}
int showCoin() {
return coin;
}
and for a test class, I need an array list with a couple of coins in it (i.e. ONE_POUND, TWO_POUNDS) and a loop that adds together the values of the coins in the list and prints the result. How can I do this?
I have the following method:
public static void doSomething(List<? extends GenericClass> input)
{
// op
}
^
This compiles and works, ensuring I can only pass in a List of a type extending GenericClass.But now I want it to accept an Array instead of List. This is where I'm stuck:
public static void doSomething(<? extends GenericClass>[] input)
{
// op
}
^
A wrong guess at the syntax which does not compile. One solution is to convert Array into ArrayList before calling the 1st method above, but I'd rather bypass this if possible.