so basically what i'm trying to do is add TWO methods under the calculateMPG method which both need the result of calculateMPG. i.e. if calculateMPG < 15 your car is a gas hog, else your car is an economy car. i tried storing calculateMPG's result into a variable, and writing the two new methods that way, but being either inside OR outside of the calculateMPG method, the program can't seem to find it to reference for the two new methods. here is what i'm working with:
class Car
{
// instance variables
double startMiles; // Stating odometer reading
double endMiles; // Ending odometer reading
double gallons; // Gallons of gas used between the readings
[code]...
again, i tried creating a reference variable for the result of calculateMPG but everywhere i put it when MilesPerGallon ran, it could not find that variable. i have a feeling this is something simple that i'm overlooking, but i'm hitting a wall and would love any input!
This current one is to calculate a planes holding pattern. I have to write a method to prompt user to enter speed in knots, then it converts it to km/hr. Another method to calc. pattern width using the speed, another method to calc. pattern length, than a main method which would call and print out the speed in knots, speed in km, pattern width and length.My current problem is on the second method. It works in that I can enter the values and it gives me the correct answers, however it's asking me to enter the speed twice, instead of just once. Anything I try just results in errors and won't compile.
import java.util.Scanner ; //main method public class TitleRemoved { public static void main(String[] args) { double airSpeedKm = airSpeedOts () ; System.out.println("That speed is " + airSpeedKm + " km/hr.") ;
[code].....
I want my code to not only work, but be organized and easily readable as well, so I want to avoid bad habits.
Right now I have 12 methods, each roughly 40 lines long, and I am contemplating whether I should simplify some of the pairs (12 methods, but every other method is very similar to each other, so 6 pairs) into one method.
The main pro of simplifying them is that my class will be much smaller, right now its about 555 lines of code. However a con is that it might not be as straight forward, at first glance at least.
Here is what I am talking about. Two original methods that are very similar:
void rotateRightClockwise(int rotations){//rotates FRONTS's RIGHT! CONFIRMED String a, b, c;//temp values for(int i = 1; i <= rotations; i++){//confirmed a = cube.cube[1][2].square[2];//3 b = cube.cube[1][2].square[5];//6 c = cube.cube[1][2].square[8];//9
[Code] ....
The only difference between these two methods, other than the last chunk for each method, is the I have to change the 2nd square bracket, [], values from lines 9-23 for cube[][]. That's it. So I am thinking of combining them into something like this...
private void rotateRight(int rotations, int x, int y){ String a, b, c;//temp values for(int i = 1; i <= rotations; i++){//confirmed a = cube.cube[1][2].square[2];//3 b = cube.cube[1][2].square[5];//6 c = cube.cube[1][2].square[8];//9
[Code] .....
And then after calling this similar method, I would finish off the last chunk from each methods, since they are too different (ie lines 26-38).
The reason why I ask this is because I am trying to build up my portfolio and I want to know if the employer would look at this and say "that was a good move by compacting your code" or "this is not that straight forward".
I have a question about a method I have. In my game, I had a move method to move my player left and right, and originally this method was huge, as it also took care checking collisions and a few other things. I broke it up a bit and put the collisions in their own methods and call them from again another method... Here is an extract which I hope illustrates my point:
private static final double MOVE_SPEED = 0.2; private static final double MAX_MOVE_SPEED = 3.5; private static final double STOP_SPEED = 0.18; private double xPos; private double yPos;
[Code] .....
Something I thought might be a good idea is to check the direction collision when im doing the calculations for that direction:
Then I thought instead i can check it after both of these steps:
if(moveLeft || dx < 0.0) { checkLeft(); }
I guess my question is quite general: How much is acceptable to break up a method? How many chains of method calls is acceptable? Is it ok to call the same method from different nearby places?
a. Create an application named ArithmeticMethods whose main() method holds two integer variables. Assign values to the variables. In turn, pass each value to methods named displayNumberPlus10(), displayNumberPlus100(), and displayNumberPlus1000(). Create each method to perform the task its name implies.
b. Modify the ArithmeticMethods class to accept the values of the two integers from a user at the keyboard.
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:
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.
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'd like to know how to return a new array, I wrote in a method below the main method. I want to print the array but system.out.print doesn't work for arrays apparently. What structure i should use?
I have to write a method called censor that gets an array of strings from the user as an argument and then returns an array of strings that contains all of the original strings in the same order except those with length of 4. For example if cat, dog, moose, lazy, with was entered, then it would return the exact same thing except for the words with and lazy.
Currently, my code so far just prints [Ljava.lang.String;@38cfdf and im stuck.
import java.util.Scanner; public class censorProgram { public static void main (String args[]){ Scanner input = new Scanner (System.in); System.out.println ("How many words would you like to enter?"); int lineOfText = input.nextInt();
[Code] ....
I have to make new string array in the method and return words without four letters in the main method
Alright, I don't understand how to link my compress method to my return statement method "getPText". Also in my compression I only want it to compress for 3 or more consecutive letters.
I have two classes (Daughter and Son) that contain some very similar method definitions:
public class Family { public static void main(String[] args) { Daughter d = new Daughter(); Son s = new Son(); d.speak(); s.speak();
[Code] .....
Each of those classes has a "speak" method with two out of three lines being identical. I could move those into a parent class, but I need each of the child classes to continue to exhibit its unique behavior. I'm trying the approach below, which replaces the unique code with a call to a "placeholder" method that must be implemented by each child class:
public class Family { public static void main(String[] args) { Daughter d = new Daughter(); Son s = new Son();
[Code] .....
This works and moves the shared code from two places (the Daughter and Son classes) into one place (the new Mother class, which is now a parent class of Daughter and Son). Something about this feels a bit odd to me, though. It's one thing for a child class to override a parent class's methods to extend or alter their behavior. But, here, I've implemented an abstract method in the parent class to alter what happens when the parent class's method (speak(), in this case) is called, without overriding that parent class method itself.
I am just trying to test this array, for a locker combination program that involves classes...but the array is printing out the whacky numbers for the location. When I try to call the method in the main, it does not work. How do I call a method that exist within a class into the main method?
public class locker { public static void main(String[] args) { CombinationLock();
I am currently working on a dice game. I have a private method called rollDice and it performs the action of rolling two dice. For my project, I need to create another method called playerRolls and I am supposed to invoke the rollDice method in the playerRolls method and perform actions based off of that. My question right now is how do I invoke a method into another method of the same class?
I need to write a method that will consume string representation of Object type and will return one object of this type. How to set return type for the method in this case?
Here is exmaple :
public <?> identifyType(String typeString){ if (typesString.matches("String")){ return new String(""); }else if (typeString.matches("Integer")){ return new Integer(0); } //....etc..}
Java-code, When i compile the java doc. I get output;
Perceptron.java:12: learn(Instance[],int,int) in Perceptron cannot be applied to (Instance[],int) PerceptronModel model = learn(train_data,5); ^ 1 error
And here is the code
import java.io.*; public class Perceptron { public static void main(String[] args) throws IOException { DataReader reader = new DataReader(); reader.init(args);
I'm working on a simple 2D Game Framework. Currently it's creating a window, but I'm working on an update method.
I constantly export the framework as a .jar file, and I've added it to the game's build path (using eclipse). I wonder if I can check all classes in the game-project (the project in which I've refecrenced the Framework in) for a specific method (for example update()) and call all found methods with that name from the framework's main class, like this:
public class FrameworkClass1 { private void checkForUpdateMethods() { // Check for update methods on program start } public void update() { runAllFoundUpdateMethods(); // Run all update methods found in the scan } }
I want to do this because it would be a simple way to update and render the game. If the main game-class look something like this:
public class Game { public void update() { // Update the game every time this is ran } }
it will be automatically updated, because it contains a method named update(), instead of naming the main game-class with a specific name etc. It will simply be more flexible that way!
I have written two methods called "contains" and "overlaps". The method "contains" is to detemine whether a point (x, y coordinate) is within the surface area of a square object. The location of the square objects is determined by the location of the upper left corner of the square.The method "overlaps" is to determine whether two square objects overlap each other.
I have written these as two separate methods. However I want to change the method "overlaps", so that it uses the method "contains" within it. I.e. using a method within a method. Thereby hopefully making the "overlaps" method a bit more clear and easy to read.
Java Code:
/** Returns true of the point with the coordinates x,y, are within the square. */ public boolean contains(int x, int y){ int sx = location.getX(); //"location" refers to a square object int sy = location.getY(); // getX() and getY() are to find it's coordinates // "side" is the side length of the square if (x >= sx && x <= (sx + side) && y >= sy && y <= (sy + side)){
Below is the main class of a project ive been working on, the goal is to start a countdown specified by the user. When the countdown reaches zero the base drops in the song that is being played. (Its not done yet) The main problem that arises is the fact that my song plays, and AFTER that, the timer starts.
Output:
Please input countdown in HH:mm:ss format. 00:00:41 Start? Yes
The name of of the song is: Skrillex & Damian "Jr Gong" Marley - "Make It Bun Dem"
The time of base drop is: 00:00:41 //Song starts here
//Song is done //Then timer starts 00:00:41 00:00:40 00:00:39
I have following code. In this code CSClient is an interface. All methods of CSClient are implementaed in CSClientImpl class. Do I not need CS Client Impl imported in this code ?
How can I call getBranch() of CSClient, which is not implemented in CSClient as " this. getCsClient(). get Branch (new CSVPath(vpath), true);" ? This code works fine without any error in eclipse.
How can a method getBranch(), which is implemented in CSClientImpl class be used in this code without importing CSClientImpl ?
Write the header for a method named send that has one parameter of type String, and does not return a value.Write the header for a method named average that has two parameters, both of type int, and returns an int value.
I have had to create a text analyser. I have created the program but it is all within the main method. The specification states that I have to have at least two methods within my Program.
import java.io.*; import java.text.SimpleDateFormat; import java.util.*; import javax.swing.*; import javax.swing.filechooser.FileNameExtensionFilter; public class Analyser { public static void main(String[] args) throws FileNotFoundException, UnsupportedEncodingException {
I'm working on a side project, which will eventually hopefully be a Pokedex, and I've just been going to it at the end of every chapter and using the stuff I've learned to work on it.So I just read chapter 3, which is all about variables and teaches how to use arrays.
my question is, does an array have to be declared inside a method? Because I'm trying to create an array inside a class without any methods and without the main, and I continuously get errors. Here's a quick working of my code that won't compile.
class blah { blah a[] = new blah[7]; a[0] = new blah(); }
The error message focuses on a[0] = new blah(); Telling me the 0 should be a ], the = is an illegal start of type, so on and so forth. The program compiles completely fine if it's within a method, like this:
class blah { void a() { blah a[] = new blah[7]; a[0] = new blah();
}
}
Or if I have public static void main (String[]args); But I'm trying to practice working outside of main.So does an array have to be within a method,
