Programming Articles - Page 2190 of 3366

In C++, we use different namespaces. We can also create our own namespaces. For example, generally, we use standard namespace called std. We write the syntax like:using namespace std;In the standard library, it contains common functionality you use in building your applications like containers, algorithms, etc. If names used by these were out in the open, for example, if they defined a queue class globally, you'd never be able to use the same name again without conflicts. So they created a namespace, std to contain this change.The using namespace statement just means that in the scope it is present, make ... Read More

An interface having only one abstract method is known as a functional interface and also named as Single Abstract Method Interfaces (SAM Interfaces). One abstract method means that either a default method or an abstract method whose implementation is available by default is allowed. The instances of SAM interfaces are java.lang.Runnable, java.awt.event.ActionListener,  java.util.Comparator and java.util.concurrent.Callable. The SAM interfaces can be implemented using lambda expressions or method references.Syntax@FunctionalInterface public interface Changeable {  public void change(T o); }Example@FunctionalInterface interface MyInterface {    String reverse(String n); } public class LambdaReverseTest {    public static void main( String[] args ) {       MyInterface myInterface = (str) -> { // ... Read More

Consider there are two friends and now they want to test their bonding. So they will check, how much compatible they are. Given the numbers n, numbered from 1..n. And they are asked to rank the numbers. They have to find the compatibility difference between them. The compatibility difference is basically the number of mismatches in the relative ranking of the same movie given by them. So if A = [3, 1, 2, 4, 5], and B = [3, 2, 4, 1, 5], then the output will be 2. The compatibility difference is 2, as first ranks movie 1 before ... Read More

Suppose we have two sorted arrays and a number x, we have to find the pair whose sum is closest to x. And the pair has an element from each array. We have two arrays A1 [0..m-1] and A2 [0..n-1], and another value x. We have to find the pair A1[i] + A2[j] such that absolute value of (A1[i] + A2[j] – x) is minimum. So if A1 = [1, 4, 5, 7], and A2 = [10, 20, 30, 40], and x = 32, then output will be 1 and 30.We will start from left of A1 and right from ... Read More

To parse a CSV file in PHP, the code is as follows. Under fopen(), set the path of the .csv file−Example$row_count = 1; if (($infile = fopen("path to .csv file", "r")) !== FALSE) {    while (($data_in_csv = fgetcsv($infile, 800, ", ")) !== FALSE) {       $data_count = count($data_in_csv);       echo " $data_count in line $row_count: ";       $row_count++;       for ($counter=0; $counter < $data_count; $counter++) {          echo $$data_in_csv[$counter] . "";       }    }    fclose(infile); }Code explanation − The file can be opened in reading ... Read More

The 'foreach' is slow in comparison to the 'for' loop. The foreach copies the array over which the iteration needs to be performed.For improved performance, the concept of references needs to be used. In addition to this, ‘foreach’ is easy to use.ExampleBelow is a simple code example − Live DemoOutputThis will produce the following output −This completed in 0.00058293342590332 seconds This completed in 0.00063300132751465 seconds This completed in 0.00023412704467773 seconds This completed in 0.00026583671569824 seconds

The property_exists() or the isset() function can be used to check if the property exists in the class or object.SyntaxBelow is the syntax of property_exists() function−property_exists( mixed $class , string $property )Exampleif (property_exists($object, 'a_property'))Below is the syntax of isset() function−isset( mixed $var [, mixed $... ] )Exampleif (isset($object->a_property))The isset() will return false if the ‘a_property’ is null.ExampleLet us see an example − Live DemoOutputThis will produce the following output−bool(true) bool(true)

To get the subdirectories present in a directory, the below lines of code can be used −Example Live DemoOutputThis will produce the following output. The glob function is used to get all the subdirectories of a specific directory−Array (    [0] => demo.csv    [1] => mark.php    [2] => contact.txt    [3] => source.txt )To get only the directories, the below lines of code can be used−ExampleOutputThis will produce the following output. The glob function is used by specifying that only directories need to be extracted−Array (    [0] => example    [1] => exam    [2] => log )

The parse_url and parse_str functions can be used to get the ID of a specific YouTube video.Example Live DemoOutputVX96I7PO8YUIn the above code, the parse_url function takes in a string and slices it into an array of information. The element that the user specifically wants to work with can be specified as a second argument or the entire array can be used.A YouTube video has an ID that can be seen in the URL. The goal is to fetch the ID after the letter ‘v’ and before ‘&’. To accomplish this, the parse_str function can be used. It is similar to GET ... Read More

The resultant value of var_dumo can be extracted to a string using ‘output buffering’. Below is an example demonstrating the same −Example Live Demo