Type Mismatch - Cannot Convert From Void To JTextField
Jun 9, 2014
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!
View Replies
ADVERTISEMENT
Apr 20, 2014
I have a simple doubt
float k = 0;
k+=0.2;
k=k+0.2; // here compilation error
compliation error Type mismatch: cannot convert from double to float
My question is why not a complilation error at k+=0.2;
View Replies
View Related
Feb 16, 2014
I'm trying to make a puzzle that gets the user input and moves the rows either to the left or right, the columns move either up or down depending on what the user wants. The problem I'm getting is a type mismatch for my RL method which moves the rows to the left.
import java.util.*;
import java.io.*;
public class Numbrosia {
static int [][] board = new int [5][5];
public static void main(String[]args){
Scanner scan = null;
try{
[code]....
View Replies
View Related
Aug 14, 2014
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??????
View Replies
View Related
Jun 12, 2014
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
View Replies
View Related
Mar 22, 2015
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 Related
May 1, 2015
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] .....
View Replies
View Related
Dec 4, 2014
I'm trying to parse and compare the content of a zip file. However I'm stuck at what SHOULD be a very simple problem, however I can't seem to find a solution. I have done the following:
ZipInputStream zin1 = new ZipInputStream(fin);
ZipEntry ze1 = null;
fin2 = new FileInputStream(fileName2);
ZipInputStream zin2 = new ZipInputStream(fin2);
ZipEntry ze2 = null;
//fin.close();
ze1 = zin1.getNextEntry();
ze2 = zin2.getNextEntry();
Which gives me the first entry of each zipfile as a ZipEntry type object. I have tried getting the path of the file (inside the zip file) and using this to create a File type object. This does not seem to work though I get:
Exception in thread "main" java.io.FileNotFoundException: My DocumentsmetadatacoreProperties.xml (The system cannot find the file specified)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(Unknown Source)
at java.io.FileReader.<init>(Unknown Source)
And this is because I get a null return from trying to create the File file1 = new File(correctLocation);
I guess I cannot access the file inside a zip file this way. So my question is how can I make a ZipEntry type object into a File type object?
View Replies
View Related
Jun 25, 2014
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] .....
View Replies
View Related
May 1, 2015
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]....
View Replies
View Related
Oct 27, 2014
This code is directly from Swing: I'm using Eclipse and keep getting an error on line 10 saying :
"The type JTextField must implement the inherited abstract method ActionListener.actionPerformed(ActionEvent)."
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
[Code] ......
View Replies
View Related
Feb 11, 2015
I am trying to read contents from a file and display them to the user. However, when I enter the file into the program I get the following error: "exception in thread 'main' java.util.MismatchException. What am i doing wrong?
import java.util.Scanner;
import java.io.*;
public class Project1{
public static void main(String[] args) throws FileNotFoundException {
double balance;
double item1Price;
[code]....
View Replies
View Related
Nov 2, 2014
import java.util.*;
public class CalculatorProjectVincent {
public static void main(String[] args) {
System.out.println("Welcome to this incredibly uneeded and redundant calculator program!");
breaker();
Scanner kb = new Scanner(System.in);
System.out.print("Enter an expression or EXIT to end the program. > ");
[Code] ....
When I run the program and input "v 100", it gives me the following:
----jGRASP exec: java CalculatorProjectVincent
Welcome to this incredibly uneeded and redundant calculator program!
- - - - - - - - - -
Enter an expression or EXIT to end the program. > v 100
Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:909)
at java.util.Scanner.next(Scanner.java:1530)
[Code] ............
View Replies
View Related
Feb 27, 2015
I am trying my code which catches exception when mismatch variable is inputed as i read it with Scanner. It seems right for me but whenever i run it, it keeps leaking memory or something like that
Code :
import java.util.*;
public class Exercise10_1 {
static Scanner scanner = new Scanner(System.in);
public static void main(String[] args) {
boolean exception;
do
[Code] .....
View Replies
View Related
Sep 15, 2014
what is different between void main() and public void main()
View Replies
View Related
Nov 27, 2014
I have written the following code to calculate tax payments based on income and filing status :
import java.util.Scanner;
public class computeTax {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
// prompt for filing status
System.out.println("enter '0' for single filer,");
[Code] ....
The while loop initiated on line 21 is there so that in case the wrong input is given at the prompt given in line 24, the program outputs "please type the right answer" with the command on line 254 before looping back to line 24 and prompting the user to enter his status number. The program works as long as the input at line 28 is an integer. Not surprisingly if the erroneous input here is not an integer, the program outputs the following error message :
Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:909)
at java.util.Scanner.next(Scanner.java:1530)
at java.util.Scanner.nextInt(Scanner.java:2160)
at java.util.Scanner.nextInt(Scanner.java:2119)
at computeTax.main(computeTax.java:28
To try to solve this I used the Try / Catch technique with the following version of the code :
import java.util.Scanner;
public class computeTax {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
// prompt for filing status
System.out.println("enter '0' for single filer,");
[Code] ....
View Replies
View Related
Apr 9, 2014
I 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);
}
View Replies
View Related
Mar 11, 2014
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.
View Replies
View Related
Apr 20, 2014
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"
View Replies
View Related
Apr 30, 2014
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?
View Replies
View Related
Apr 22, 2014
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?
View Replies
View Related
Sep 1, 2014
I 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.
}
View Replies
View Related
Nov 5, 2014
how to assert a void method like shown in the photos,
View Replies
View Related
Mar 1, 2015
I 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);
}
}
View Replies
View Related
Jul 29, 2014
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
View Replies
View Related
Jan 7, 2014
What does void and static mean in the main method?
View Replies
View Related
