Programming Articles - Page 2665 of 3366

To check if there are any selected items, use the following:boolean res = !list.isSelectionEmpty();The value of res would be TRUE IF we have a selected item in the JList.The following is an example to check if there are any selected items in JList:Examplepackage my; import java.awt.event.*; import java.awt.*; import javax.swing.*; class SwingDemo extends JFrame {    static JFrame frame;    static JList list;    public static void main(String[] args) {       frame = new JFrame("JList Demo");       SwingDemo s = new SwingDemo();       JPanel panel = new JPanel();       String sports[]= {"Squash", ... Read More

In C++, we can overload the functions. But sometimes the overloading is not done. In this section, we will see what are the different cases, in which we cannot overload the functions.When function signatures are same, only the return type is different, then we cannot overload the function.int my_func() {    return 5; } char my_func() {    return 'd'; }When the member functions have the same name and same parameter list in a class, then they cannot be overloaded.class My_Class{    static void func(int x) {       //Something    }    void func(int x) {     ... Read More

Let’s say the following is our List with string elements:List leagues = Arrays.asList("BBL", "IPL", "MLB", "FPL", "NBA", "NFL");Now, create a stream and filter elements that end with a specific letter:Stream stream = leagues.stream().filter(leagueName -> leagueName.endsWith("L"));Now, use Objects::nonnull for non-null values:List list = stream.filter(Objects::nonNull).collect(Collectors.toList());The following is an example to filter non-null value in Java:Exampleimport java.util.Arrays; import java.util.List; import java.util.Objects; import java.util.stream.Collectors; import java.util.stream.Stream; public class Demo {    public static void main(String[] args) {       List leagues = Arrays.asList("BBL", "IPL", "MLB", "FPL", "NBA", "NFL");       Stream stream = leagues.stream().filter(leagueName -> leagueName.endsWith("L"));       List list = ... Read More

Let’s say we have a String List with an empty value. Here, we have empty array elements before Football and after Squash:List sports = Arrays.asList("", "Football", "Cricket", "Tennis", "Squash", "", "Fencing", "Rugby");Now filter the empty string values. At first, we have used Predicate to negate values:Stream stream = sports.stream(); Predicate empty = String::isEmpty; Predicate emptyRev = empty.negate(); stream.filter(emptyRev).collect(Collectors.toList()));The following is an example to filter empty string values from a List:Exampleimport java.util.Arrays; import java.util.List; import java.util.function.Predicate; import java.util.stream.Collectors; import java.util.stream.Stream; public class Demo {    public static void main(String[] args) {       List sports = Arrays.asList("", "Football", "Cricket", "Tennis", ... Read More

Let us see how to generate random numbers using C++. Here we are generating a random number in range 0 to some value. (In this program the max value is 100).To perform this operation we are using the srand() function. This is in the C library. The function void srand(unsigned int seed) seeds the random number generator used by the function rand.The declaration of srand() is like below −void srand(unsigned int seed)It takes a parameter called seed. This is an integer value to be used as seed by the pseudorandom number generator algorithm. This function returns nothing.To get the number ... Read More

Let’s say the following is the String List:List list = new ArrayList(); list.add("Tom"); list.add("John"); list.add("David"); list.add("Paul"); list.add("Gayle"); list.add("Narine"); list.add("Joseph");Now, let’s say you need to filter elements beginning with a specific letter. For that, use filter() and startsWith():long res = list    .stream()    .filter((s) -> s.startsWith("J"))    .count();We have also counted the elements above after filtering using count().The following is an example to count element after filtering in Java:Exampleimport java.util.ArrayList; import java.util.List; public class Demo {    public static void main(final String[] args) {       List list = new ArrayList();       list.add("Tom");       list.add("John"); ... Read More

In C++11, the lambda was introduced. Lambdas are basically a part of, that can be nested inside other function call statements. By combining lambda expressions with the auto keyword, they can be used later.In C++14, these lambda expressions are improved. Here we can get the generalized or generic lambda. For example, if we want to create a lambda, that can add integers, add numbers, also concatenate strings, then we have to use this generalized lambda.Syntax of the lambda expression is looking like this −[](auto x, auto y) { return x + y; }Let us see one example to get the ... Read More

Let us first create a Stream:Stream stream = Stream.of("UK", "US", "India", "Australia", "Armenia", "Canada", "Poland");Now convert Stream to TreeSet:Set set = stream.collect(Collectors.toCollection(TreeSet::new));The following is an example to convert String to TreeSet in Java:Exampleimport java.util.Set; import java.util.TreeSet; import java.util.stream.Collectors; import java.util.stream.Stream; public class Demo {    public static void main(String[] args) {       Stream stream = Stream.of("UK", "US", "India", "Australia", "Armenia", "Canada", "Poland");       Set set = stream.collect(Collectors.toCollection(TreeSet::new));       set.forEach(val -> System.out.println(val));    } }OutputArmenia Australia Canada India Poland UK USRead More

In C we have seen different format specifiers. Here we will see another format specifier called %p. This is used to print the pointer type data. Let us see the example to get a better idea.Example#include main() {    int x = 50;    int *ptr = &x;    printf("The address is: %p, the value is %d", ptr, *ptr); }OutputThe address is: 000000000022FE44, the value is 50

Let us create string Stream:Stream stream = Stream.of("Bing Bang Theory", "Vampire Diaries", "Game of Thrones", "Homecoming");Convert the above string stream and join them with Collectors:final String str = stream.collect(Collectors.joining(" "));The following is an example to convert string Stream to join them:Exampleimport java.util.stream.Collectors; import java.util.stream.Stream; public class Demo {    public static void main(String[] args) {       Stream stream = Stream.of("Bing Bang Theory", "Vampire Diaries", "Game of Thrones", "Homecoming");       final String str = stream.collect(Collectors.joining(" "));       System.out.println("Join result..."+str);    } }OutputJoin result... Bing Bang Theory Vampire Diaries Game of Thrones HomecomingRead More