comparator and comparable in java interview questions

). CompareTo (keyextractor.apply (C2)); } Public StaticSuperT>keyextractor) {objects.requirenonnull (keyextractor); return(ComparatorSerializable) (c1, C2)-Integer.compare (Keyextractor.applyasint (C1), Keyextractor.applyasint (C2)); } Public StaticSuperT>keyextractor) {objects.requirenonnull (keyextractor); return(ComparatorSerializable) (c1, C2)-Long.compare (Keyextractor.applyaslong (C1), Keyextractor.applyaslong (C2)); } Public StaticSuperT>keyextractor) {obj

Comparable introduction Comparable is the sort interface. If a class implements the comparable interface, it means "this class supports sorting." The class that implements the comparable interface supports sorting, assuming that there is now a list (or array) of objects for the class that implements the

The Java comparator has two classes, namely the comparable interface and the comparator interface .When sorting an array of objects, the comparator works very clearly, first of all, to explain the comparable interface. Let the obj

interface is to define a custom class's comparison rules, because the CompareTo method has only one parameter and the other parameter is this, which is the class itself, so we can think of it as defining a comparison rule within the class. The equivalent of a Java developer writing a string class should allow it to implement the comparable interface. However, the Compare method has two parameters, which ca

In our usual use of collection, it is very often necessary to sort the elements inside. For this sort, there are usually two ways to implement this:1. Create a comparator class to implement the comparator interface, and then apply the sort method provided by the collection internally. For example, the edges in the graph are sorted by their weight size (the second method is also described in the following ex

());int v2 = Math.abs(((Integer) o2).intValue());return v1 > v2 ? 1 : (v1 == v2 ? 0 : -1);}} Use AbsComparator to sort the set: Import java. util. *; public class Test {public static void main (String [] args) {// generate an array of 20 Random integers (with positive and negative values) Random rnd = new Random (); integer [] integers = new Integer [20]; for (int I = 0; I Use the Comparable interface t

); +}Before ordering: [{age=1}, {age=4}, {age=2}, {age=7}, {age=9}, {age=8}, {age=3}, {age=0}, {age=1}] After sorting: [{age =0}, {age=1}, { Age=1}, {age=2}, {age=3}, {age=4}, {age=7}, {age=8}, {age=9}]3. Summary comparisonComparable defines the collation within the class, Comparator defines the collation externally, comparable the equivalent of an "internal sequencer",

Same Both comparable and comparator are used to implement object comparisons, sorting To compare and sort objects, you need to implement comparable or comparator interfaces Comparable and comparator are all

Comparableand is the Comparator interfaces provided by Java Core API. From their names, we can tell they is used for comparing stuff in some. But what exactly was they and what is the difference between them? The following is examples for answering this question. The simple examples compare the size of the HDTV ' s. How to use comparable vs.

The Java comparator has two classes, namely the comparable interface and the comparator interface. The comparer has a very large effect when sorting an array of objects 1, using the comparable interface, you need to rewrite the compareTo(T o) method, where the collation is d

Java provides a comparable interface that contains only one CompareTo () method. This method can be used to sort two objects in a single order. Specifically, it returns a negative number, 0, a positive number to indicate that an existing object is less than, equal to, greater than the input object.Java provides a comparator interface that contains two methods of

};Java.util.Arrays.sort (stuarray);For (Student Stu:stuarray) {System.out.println (stu.getname () + "," +stu.getage ());}}} Usage of comparator: Package test;public class Student1 {Private String name;private int age;Public Student1 (String Name,int Age) {THIS.name = name;This.age = age;}Public String getName () {Return name;}public void SetName (String Name) {THIS.name = name;}public int Getage () {Return age;}public void Setage