I am asked to create a code that if a user enters 1 it will use the object natural comparison form ('default') as written in CompareTo method.But if he chooses to enter something else then another comparison is used.Maybe I just need to use 2 diff comparators? but then what;s the point of defining something as 'default'....
Which of the following classes uses Comparable and Comparator?
QueueTreeSetStackPriorityQueue
In the above question, what does 'uses' mean? Does it mean do above classes implement Comparable and Comparator?
I know that in order to compare any two elements stored in one of the above classes, we need to make the elements' class to implement one of these - either Comparable or Comparator.
So I built this comparator exactly the same way I built my others that are working.But the comparator for UserComparator is not being found for some reason.I will post my usercomparator class and JSP page.
TextButton up = new TextButton("up", textButtonStyle);
and .addListener is just one of the methods "TextButton" has (actually I think its inherited from "Button" but that doesn't matter).
Basically my question is what's going on inside the parentheses? From what I see its a new instance of "ClickListener" but then suddenly they override an actual method within. Is this simply just a way to override a method from the ClickListener class or is it something else?
So, this is weird for me because I don't really understand why the BorderLayout class constructor is being initialized as a parameter for the setLayout..
Java SE Runtime Environment build 1.8.0..This is part of the code:
public static int addAddress (String[] number, boolean[] front, double[] total) { int num = 0; double ffee = 0; /*boolean value = false;*/
[code]...
I have tried using the line of code commented out, /*boolean value = false;*/. However, another error is displayed. The compiler shows the following...
Inspection.java:33: error: incompatible types: boolean cannot be converted to boolean[] front[num]= defineFront(num, value); ^ Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output error...I know that boolean values are by default stored as false, once you create the array. However, I'm having trouble passing the variable to the method.
Now, i have an array of Client, so I would like to enter within this. Example:
public void addClient(Client c){ for (int i = 0; i<client.length ; i++) { // client is an array of Client object client[i] = c; // Enter a c in the array, but does not work! System.out.println("test "+clienti[i]); // print Client@15db9743 } }
I have used the println for check if worked insertion, but the result shows no
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.
I have a drop-down which contains the four sections simple buttons(filters). When click any of these buttons some settings are applied. I have successfully auotmated it using simple if else and switch but in that case i have to use 8 parameters(8 are the number of button)
public void editFilters(WebElement filter1, WebElement filter2, WebElement filter3, WebElement filter4,WebElement filter5,WebElement filter6,WebElement filter7,WebElement filter8 String edit, String expectedColour) { switch (edit) { case "selectFilter": if (filter1 != null) {
[Code] .....
But want to make it more effective by using hashes. I do not want to use 8 different parameters to perform action on the respective button.
So now what i want to implement.
Create a method in which i pass the parameter1 as hash and 2nd parameter as 0 or 1, 0 means unSelectFilter and 1 means select the filter.
With parameter 1, in code i want to pass the name or xpath or anything else for any number of filters , that those filters names should be stored into that hash and then by passing 0 or 1, i can select/unselect those filters.
I am following this article [URL] .... till now I have made some code
This is my Interface
public interface Comparable<T> { public int compareTo(T o); }
And this is my class where I am using Bound Type Parameter on Generic Methods
public class GenericMethodBoundType { public static <T extends Comparable<T>> int countGreaterThan(T[] anArray, T elem) { int count = 0; for (T e : anArray)
[Code] .....
What else I need to do both in main method and at what parameterized types I need to pass at the class?
Write a method named hopscotch that accepts an integer parameter for a number of "hops" and prints a hopscotch board of that many hops. A "hop" is defined as the split into two numbers and then back together again into one.For example, hopscotch(3); should print:
byte b = 100; it works (implicit conversion of implicit int literal 100 to byte.
But if you have a methodvoid bla(byte b){}
And want to invoke it with a literal (which is an int by default):bla(8) then there is no implicit conversion.
Is the byte b = 100; just an exception in Java? And is it the rule that one has to explicitely cast (narrow) integer literals when passing to smaller-than-int types?
so i have this question where it wants me to create a recursion method that takes ONLY THE ARRAY as a parameter, and without using loops or static variables inside the method, and then the method returns the smallest value in that array. However, i tried making the simple if statements where i compare the first element of the array with the second element using the length of the array and decreasing it to get the next elements and compare it again by calling the recursion method, but the problem is when i call the method again, the length does not decrease, even if i store it in a variable, the variable will initialize itself again, and the length wont change.
In my book for learning java, one of the questions asks us to create a method header named convertTOKM that takes an int parameter, which is the number of miles, and returns a double value for the converted value in kilometers. I made one, but wanted to know if I was right in any way.
Here it is:public double convertTOKM(int miles, double kilometers){
I'm doing an assignment where a method receives a Queue as a parameter then convert it into a stack, I made it but now I want to try it in my main, but how can I do this? there's no toString and I cant use a for loop because I'm using a queue and not an array. This is the head of my method:
I am practicing some basic recursion and I was trying to solve this problem
Write a method sumTo that accepts an integer parameter n and returns the sum of the first n reciprocals. In other words:
sumTo(n) returns: 1 + 1/2 + 1/3 + 1/4 + ... + 1/n
For example, the call of sumTo(2) should return 1.5. The method should return 0.0 if passed the value 0 and should throw an IllegalArgumentException if passed a value less than 0.
This is my attempt to do it , however my output is always a 0.0 , and i do not understand why :
public static double sumTo(int n ){ if(n<0){ throw new IllegalArgumentException(); } else if (n==0){ return 0.0;
i have to "Write a method called addToOverThirty which takes the array nums3 as a parameter. It adds 1 to all numbers that have a value greater than 30 in the array.
Add a call to the addToOverThirty method, then display a message telling what the output is followed by the results For example:The nums3 array after adding 1 to all numbers greater than 30 is10 6 15 and so on (check with the values you assigned to nums3)"its pointless because we were told not to make the array have a number over 30.
import java.lang.*; import java.util.*; public class LastProject public static void main(String[] args) { int nums1[] = new int[15]; int nums2[] = new int[15]; int nums3[] = {5,2,15,8,26,22,1,29,4,23,30,11,19,6,24};
I have two methods with parameters out of the main method, both of them work fine alone but I am finding a problem to use them together. I need to use the parameter of Method one in the second Method.
I am trying to sort an ArrayList of objects with the comparator as I want to sort based on a certain value for each object. I understand I would need to override compareTo() in the objects class, is there any way I can get around also needing to override for all subclasses of the object?
I had a TestColor class which contained methods to change hue, saturation, brightness, red, green, blue of TestColor's instances but also had static methods which take in an additional parameter for an instance of TestColor and returns the affected instance of TestColor. Now instead of having one method for every possible color effect to be applied to an image, how can I have one method that takes in an Image parameter, a static or non-static method reference from TestColor parameter and lastly an intensnity value parameter. This is so that I can make an affectedImage object instance inside the method and a Graphics2D object for drawing to each pixel of the new image, now I have one for loop and one nested for loop for the x and y pixels of width and height of the old image and inside the nested for loop I'd create a TestColor by calling getRGB on the image's pixel. Then I would apply the static or non-static method reference somehow to change the color with the intensnity value and after applying it draw to the new Image with Graphics2D. How to would I parametize a method reference and be able to use it in such way?
public class Someone { String name; int age; ArrayList <Someone> listarr = new ArrayList <Someone>(); public Someone(String name1, int age1) { name = name1; age = age1;
[code]...
1. In the compare method, what happens when it returns one of the 0, -1, or 1? How does returning such values contribute to the sorting process? How does it take in information (like I know it does through the parameters, but how exactly)?
Something about implementing Comparator interface isn't very clear to me: overriding the compare method.
Like here for example:
//This sorts a list of objects holding information based on age: the name and the age of the person
public class Person { String name; int age; public Person (String name, int age) { this.name = name; this.age = age;
[Code] ....
What exactly is happening behind the scenes? I don't understand mostly the part where it returns a 0, a 1, or a -1. After it returns one of those values, what really happens next?
For the displaying of the list, is the method toString() being accessed to output the list in the System.out.println statement?
