I want to write a method which would give us a rectangle with numbers. The input is an integer which represents the length of a line in rectangle and the result type is void. The example for n=4 is:
3210
0321
1032
2103
My GUI class:
import java.awt.FlowLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JPasswordField;
[Code] ....
Eclipse error message:
Exception in thread "main" java.lang.Error: Unresolved compilation problem:
Type mismatch: cannot convert from void to JTextField
at GUI.<init>(GUI.java:58)
at Apples.main(Apples.java:7)
I copied this from a thenewboston tutorial and he uses an old version of java but im pretty sure ive copied character for character!
I get an error in a program "void is an invalid type for the variable action performed"
Here is the code of my program.
import java.awt.EventQueue;
import javax.swing.JFrame;
import java.awt.Label;
import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.TextArea;
[Code] .....
I am new to Java and trying to learn it.I wrote the following program but while creating the method nav i am getting errors.
Error:- void is an invalid type for the variable nav
import org.openqa.selenium.*;
import org.openqa.selenium.firefox.FirefoxDriver;
import java.util.*;
public class YahooHomepage {
private static WebDriver driver;
[Code] .....
Here is part of my program that contains the code giving me problems.
import java.awt.EventQueue;
import javax.swing.JFrame;
import java.awt.Label;
import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.TextArea;
import java.awt.Choice;
import javax.swing.JRadioButton;
[code]....
What I'm trying to do is basically draw a Rectangle outline through left-click and then dragging the mouse to the size one wants.
After one has created this rectangle, the user can change the color of the rectangle through clicking the 3 sliders found on the top in the program. Upon the change in color, the rectangle should change from "g.drawRect" to "g.fillRect" and use the desired color.
I have the basic outline of the program done, but working with the last part (the color and changing of the Rectangle type after changing the color)
Is there like a "then" command in Java? Like: after you've done x, do y. That would make this heaps easier.
import java.awt.event.*;
import java.awt.*;
import java.applet.*;
//Diese Applikation offnet ein Fenster,
//in welchem durch einen gehaltenen linken Mouse Klick
//ein Reckteck gezeichnet wird
public class WhatIsTheProblem006 extends Applet
implements AdjustmentListener {
[Code] ....
I tried to create file and write the output of my program in it in java when i use WriteLong then the file does not contain long value, how I create this file my program is to print prime numbers between 500000 to 10000000
public class primenumber {
public static void main(String[] args) {
long start = 5000000;
long end = 10000000;
System.out.println("List of prime numbers between " + start + " and " + end);
for (long i = start; i <= end; i++) {
if (isPrime(i)) {
System.out.println(i);
[Code] ....
I got this code with mode methods. The results is not exactly what I want.
Code:
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Random;
import java.util.*;
public class ProcessMarks {
private static final int NMARKS = 125;
[Code] ...
Result (it's repeat number):
*Mode is = 53
*Mode is = 53
*Mode is = 53
*Mode is = 53
*Mode is = 53
*Mode is = 62
*Mode is = 62
*Mode is = 62
*Mode is = 62
*Mode is = 62
*Mode is = 67
*Mode is = 67
*Mode is = 67
*Mode is = 67
*Mode is = 67
*Mode is = 77
*Mode is = 77
*Mode is = 77
*Mode is = 77
*Mode is = 77
*Mode is = 78
*Mode is = 78
*Mode is = 78
*Mode is = 78
*Mode is = 78
*Mode is = 85
*Mode is = 85
*Mode is = 85
*Mode is = 85
*Mode is = 85
Result that i want it to be (number appear only once):
*Mode = 53, 62, 67, 77, 78, 85
or
*Mode is = 53
*Mode is = 62
*Mode is = 67
*Mode is = 77
*Mode is = 78
*Mode is = 85
I am having problems with writing a simple program to see if a number is divisible by 6.
public void run() {
println("This program will display all numbers divisible by");
println(" 6 between 1 and 100.");
int x =1;
boolean divide =(x%6==0);
[Code] ....
It is telling that every number is not divisable by 6?
Write a program that will read two numbers and an integer code from the keyboard. The value of the integer code should 1, 2, 3, 4. If the value of the code is 1, compute the sum of the two numbers. If the code is 2, compute the difference (first number minus second). If the code is 3, compute the product of the two numbers. If the code is 4, and the second number is zero, compute the quotient (first divided by second). If the code is not equal to 1,2,3,4, display an error message. The program is then to display two numbers, the integer code and the computed result to the screen
here is the code that I have so far:
public static void main(String[] args) {
Scanner read = new Scanner (System.in);
int num1, num2, code, sum;
System.out.println("Please enter a number");
num1 = read.nextInt();
[Code] .....
for (int i = 0; i < letters.length; i++) {
double relativeFreq = (onesAverage()/letters[i]);
char a = characters.charAt(i);
double j = score[i];
System.out.printf();//ToDo
Above is my current code. Basically- There is a string called characters of length 26 (1 char for each letter in alphabet), a double relativeFrequency value which does a calculation and the end result is a number with lots of decimal numbers. The score array has set double values within the array.
What I want to do is create a print f statement where I print out each of the values I initialized above WITH specific amounts of spaces in between. So it should be in this order:
a (spaces) j (spaces) relativeFreq (newLine).
Between J and relativeFreq there should be 4 spaces, however if the value in relativeFreq is greater than 10 (it won't be greater than 100)- then there should be 3 spaces. Everytime I try to create a printf statement my code ends up crooked for some of the values.
for (int i = 0; i < letters.length; i++) {
double relativeFreq = (onesAverage()/letters[i]);
char a = characters.charAt(i);
double j = score[i];
System.out.printf("%c %.4s %.4s%n",a, j, relativeFreq);
Write method distance to calculate the distance between two points (x1, y1) and (x2, y2). All numbers and return values should be of type double. Incorporate this method into an application that enables the user to enter the coordinates of the points.
Hints:
- The distance between two points can be calculated by taking the square root of
( x2 - x1 )2 + ( y2 - y1 )2
- Use Math class methods to compute the distance.
- Your output should appear as follows:
Type the end-of-file indicator to terminate
On UNIX/Linux/Mac OS X type <ctrl> d then press Enter
On Windows type <ctrl> z then press Enter
Or Enter X1: 1
Enter Y1: 1
Enter X2: 4
Enter Y2: 5
Distance is 5.000000
Type the end-of-file indicator to terminate
On UNIX/Linux/Mac OS X type <ctrl> d then press Enter
On Windows type <ctrl> z then press Enter
Or Enter X1: ^Z
what is different between void main() and public void main()
View Replies View RelatedI know void means it doesn't return anything but to me when I think it doesn't return anything it just does equations and other things. So why can you use this? Or is Void like returning input such as a Scanner?
void printStates() {
System.out.println("cadence:" +
cadence + " speed:" +
speed + " gear:" + gear);
}
Below code I am using to typecast int to char.
char escapeValue = (char)0;
char cha = (char) 10;
escapeValue = (char)(escapeValue * cha); // Here am getting the above error.
I have 38 similar issues in my workspace.
I am trying to make a custom texture system for a block in Minecraft, I am not too advanced with Java and am not sure how to make this work the way I want it to.
Java Code:
/** The list of the types of step blocks. */
public static final String[] blockStepTypes = new String[] {"stone", "sand", "wood", "cobble", "brick", "smoothStoneBrick", "netherBrick", "quartz"};
private Icon missing;
private Icon icon1;
/**
* From the specified side and block metadata retrieves the blocks texture. Args: side, metadata
*/
[code]....
Alright, so basically I figured I could just tell the code to see if the block is made out of Stone, then to set the texture to Stone, or if it's made out of Sand, then set it to Sand.What I usually get is Eclipse telling me to "insert '!= null' check", "insert '!= null' check", and then just error out saying "Opperator != is undefined for the argument type(s) boolean null"
If you have final int i = 1;
short s = 1;
switch(s) {
case i: System.out.println(i);
}
it runs fine. Note that the switch expression is of type short (2 bytes) and the case constant is of type int (4 bytes).My question is: Is the type irrelevant as long as the value is within the boundaries of the type of the switch expression?I have the feeling that this is true since:
byte b = 127;
final int i = 127;
switch(b) {
case i: System.out.println(i);
}
This runs fine again, but if I change the literal assigned to i to 128, which is out of range for type byte, then the compiler complains.Is it true that in the first example the short variable and in the second example the byte variable (the switch expressions) are first implicitly converted to an int and then compared with the case constants?
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??????
Got a problem with generics, which I'm still pretty new at. Here's a program that compiles fine:
import java.util.ArrayList;
import javax.swing.JComponent;
public class Experiments {
public static void main(String[] args) {
ListHolder holder = new ListHolder();
[Code] ....
It's useless, but it compiles. If I change Line 14, however, to add a generic type parameter to the ListHolder class, Line 10 no longer compiles:
import java.util.ArrayList;
import javax.swing.JComponent;
public class Experiments {
public static void main(String[] args) {
ListHolder holder = new ListHolder();
[Code] ....
I get this error:
Uncompilable source code - incompatible types: java.lang.Object cannot be converted to javax.swing.JComponent
at experiments.Experiments.main(Experiments.java:10)
Apparently, the introduction of the type parameter leaves the compiler thinking that aList is of type Object. I can cast it, like this:
JComponent c = ((ArrayList<JComponent>)holder.aList).iterator().next();
That makes the compiler happy, but why is it necessary? How does adding the (unused) type parameter to the ListHolder class end up making the compiler think the aList member of an instance of ListHolder is of type Object?
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 RelatedI have a program that I have created from scratch called Product and I also created a Tester program to test my theory. The only problem that I have is that I am getting an error with this statement System.out.printf statement. The statement needs to print out "Program [name = HP ENVY x360 TouchSmart, price = $xxxxxx". The error states that "The method printf(String, Object...) in the PrintStream is not applicable for the arguments (String, String, void).
Which tells me that it is referencing back to the class file where I have
public void applyDiscount(double percent) {
percent = price - (price * percent); //establishing the discount
}
The lines of code in my tester file are (partly displayed)
String formatString = "Product[name = %s, price = %.2f]";
System.out.printf(formatString, product.getName(), product.getPrice())
//user input the discount amount
System.out.println("Enter discount percentage [0 - 100]: %.2f ");
double discount = user_input.nextDouble();
System.out.printf(formatString, product.getName(), product.applyDiscount(discount)); //This is the line giving me an error.
}
how to assert a void method like shown in the photos,
View Replies View RelatedI want to have parameters that I use the "void" for, in other words it doesn't return anything.
class code
{
void go()
{
int TestStuff t = new TestStuff();
t.takeTwo(12,34)
}
void takeTwo (int x, int y) {
int z = x + y;
System.out.println("Total is:" + z);
}
}
package input;
import javax.swing.JOptionPane;
public class Input {
public static void main(String[] args) {
int user;
user = JOptionPane.showMessageDialog(null, "Enter Your Age""); ERROR IS HERE
if(user <= 18) {
JOptionPane.showMessageDialog(null, "User is legit");
} else {
JOptionPane.showMessageDialog(null, "User is not legit");
}
}
}
I'm getting this error message :
incompatible types: void cannot be converted to int
unclosed string literal
What does void and static mean in the main method?
View Replies View RelatedI'm pretty new to Java. I was working the project about gamble. I'm having trouble with invoking the void method from another class. This is what I have done so far.
There are two classes, and I'm trying to invoke gambleAnotherRound method from gambler class into highlighted part in casino class. So, what I want to do is when the program generates "else" part, it goes back into another gamble round.
public class gambler {
public void gambleAnotherRound(double dollarsBet) {
dollarsSpent += dollarsBet;
Random randomNumbers = new Random();
double randomDouble = randomNumbers.nextDouble();
[Code] ....
Below one is casino class.
// use a System.out.print statement to ask how much money each gambler should bet.
// Then declare a variable dollarsBet of type double, and set its value to the keyboard's
// keystroke (be sure to use keyboard.nextDouble()).
// If the user enters 0, then issue a break statement, so that the while loop terminates
// Else, invoke the gambleAnotherRound method of each Gambler, and pass it the variable dollarsBet
[code] ....