comparable

问题 This question already has answers here : Closed 9 years ago . Possible Duplicates: difference between compare() and compareTo() Java: What is the difference between implementing Comparable and Comparator? What are the keys differences between Comparable and Comparator. and which is preferred over the other in what scenarios? Thanks Updated - GOOD LINK WITH EXAMPLE!! http://www.digizol.com/2008/07/java-sorting-comparator-vs-comparable.html 回答1: When your class implements Comparable, the

问题 I am implementing a heap for abstract objects. Now I was able to implement a stack as there are no comparisons required for a Stack. However the heap requires comparisons. So I have Object A , and Object B . I can ensure that the Object that are in the heap are of the same class, and that they can be ordered (that is the class has a compareTo function to know if A<B, A=B, or A>B) . But if I use A.compareTo(B) , I get a syntax error saying that compareTo is not defined for objects. I did some

问题 I've been trying to learn the comparable class for sometime now, I know the correct syntax and the how it is used in most cases. Such as: int result = ObjectA.compareTo(ObjectB); would return a value of 0 if both object is the same; a negative value if object A is less then object B ,or a positive value if A is greater then B. However when I go to actually write a program that uses the compareTo method, the compiler is saying that it can not find the compareTo method. my question is: Do I

问题 This question already has answers here : interface and a class. name clash: same erasure, yet neither overrides other (3 answers) Closed 2 years ago . For fun I'm creating a sorting framework to better understand the various sorting algorithms. And, I'm trying to make it generic enough so that it can sort anything that implements an interface that extends the comparable interface. However, the java compiler isn't happy with me. Here's my interface: public interface Sorter<C extends Comparable

问题 I am implementing a form of leftist min heap, which stores arbitrary words by length. So, I have written a wrapper class for Scanner, and changed the compareTo, like so public class ScannerWrapper implements Comparable<String> //a Scanner, sc and a String, current public int compareTo(String str){ if(current.length() > str.length()) return -1; if(current.length() > str.length()) return 1; else return 0; } where current = sc.next() and is not the \n character. in this case, if I have

问题 What is the working style of compareTo(Object o) method. How the first object of a set is compared? Every time when an object is created the constructor is called and the values are assigned with this for class variables and the same class variables are compared with Object o , but, what is o in this case? 来源： https://stackoverflow.com/questions/39752908/what-is-the-first-current-object-in-compareto-method-in-java-comparable-interf

问题 This is the comparator I wrote to to sort Nodes based on cost. public class MyCostComparator implements Comparator<Node>{ public int compare(Node a, Node b){ if(a.pathCost > b.pathCost) return 1; else return -1; } } I find that it's behaviour is different on my machine (Java 1.7) and on the Uni's server (Java 1.5). However when I make it: if(a.pathCost >= b.pathCost) , it seems to work fine on 1.5, but the other way on 1.7. Also, what's the drawback of NOT returning zero when the values are

问题 I have an generic abstract class, BString , which expects one of its types to implement Comparable . Another class, NGram extends BString , passing String as the comparable type. A final class, BinarySearchTree expects keys which extend Comparable . Why am I unable to create a BinarySearchTree with NGram as the key type? Does the implements Comparable declaration for BString strictly hold for BString and none of its descendants? I have included the class declarations below, and note that

问题 I've implemented an ArrayLinearList class on the following way public class ArrayLinearList<T> implements LinearList<T>, Iterable<T> which contains the class member protected T[] element In order to extend the functionality of the class I create a new class that inherits from the first one class SuperList<T extends Comparable<T>> extends ArrayLinearList<T> Here I ensure that the type T implements the Comparable interface (this cannot be changed). In the SuperList class I have the following

问题 I am working in an android application I want to sort a List of Objects with an Object Property . I have sorted it successfully but when I sort it all the List with that object changes the value to same as the sorted value Please look into ma code : SortedSet<Caseload> removeDuplicateClientName = new TreeSet<Caseload>( new Comparator<Caseload>() { @Override public int compare(Caseload caseload0, Caseload caseload1) { return caseload0.ClientName.compareTo(caseload1.ClientName); } }); //