Trending February 2024 # How Does Pop Function Work In Perl With Examples # Suggested March 2024 # Top 2 Popular

You are reading the article How Does Pop Function Work In Perl With Examples updated in February 2024 on the website Daihoichemgio.com. We hope that the information we have shared is helpful to you. If you find the content interesting and meaningful, please share it with your friends and continue to follow and support us for the latest updates. Suggested March 2024 How Does Pop Function Work In Perl With Examples

Introduction to Perl pop

Web development, programming languages, Software testing & others

Syntax:

The Perl script uses some data structure concepts like push and pop. It is mainly used for manipulates the data, and it reduces the memory to perform the operations quickly. The pop() functionality have to remove the last element from the array or any other data structures in the memory.

@var =(' '); print pop(@var); ----some perl script codes depends upon the user requirement the perl functions will be called and used in the file---

The above codes are the basic syntax for the pop() function used in the Perl script; the user input values are popped out on the data structures.

How does the pop Function work in Perl?

The Perl script uses some default functions, keywords, variables for creating the sophisticated applications. Likewise, we use some data structures concepts like an array, stack, queue, push, pop, shift etc., for securing the datas as well as reduce the data usages in the memory location. Perl array uses a pop() function for removing the last element of the array; it also pointed out the stack in data collections and structure concepts. It also used for to remove as well as return or pop the last element from the array.

This is meant by to reduce the number of elements in the array. Generally, the last stage or position of the element is the highest level of the index is generated automatically in the stack memory. Also, the pop() function of the elements are chopped off the elements from the right side positions of the array list, and it will return the element as soon as to reduce the element size automatically with one by one in the memory. The array elements are also thought of as the stack for the numbered boxes that are top to bottom, and increasing the element size goes down so that the bottom of the stack memory is popped out in the memory.

Examples of Perl pop

Given below are the examples of Perl pop:

Example #1

Code:

#!/usr/bin/perl -w @var = (7654,3876,2736,91237,237,9273,36483,12973,2739,918723,9273,8263,912873,9812732,973924,192873184,9210838,91723,90238,921838); print("Welcome To My Domain", pop(@var), "After using the pop() function in the script it return the value as recently removed in the list",@var, "n")

Output:

In the above example, we used a basic variable like @var to initialise the values; it will be lengthy to store them in the array. So each value has a separate reference, and it holds the reference to the stack memory location because when we removed the particular element in the stack, it also holds the reference keep on the memory so the memory loss will be occurred due to avoid the memory leaks and consumption it removes in the memory. If we use the pop() function, it removes the last element in the array that is left to right position; the last position of the element is 921838 it will be removed in the stack memory.

Example #2

Code:

use strict; use warnings; my @var = qw(+ - * / %); pop @var; print "Welcome To My Domain its the first pop() function used in the stack memory n n @varn"; print "After Inserting the aboev two operators in the stack memory the variable and the array size is shown n n @var n"; my @var1 = qw(74 dg dgh wehf whewf jh e wiejh eih eihrf 3748 jh48 hef 4897y jhef 4 9y8 hr 9 4 herfu9 jkd jdeij iejhfb wefih); pop (@var1); unshift @var1, 'Have a Nice Day User'; print "After using the unshift() function in the pop() functionality the stack memory of the varaible is shown n [email protected]n"; my @demo = ('1'..'100'); unshift(@demo, pop(@demo)); print "We compared the unshift() functionality in the pop() function the result is: n n@@demo = @@demon";

Output:

In the second example, we used some different functions like unshift and push() in pop() functionality. After removing the last element in the stack, the memory reference of the particular value has also been empty. It is in null space, so it will be occupied with the other elements by using the push() operation; it will be inserted in the array list. When we use unshift() function, we can call the pop() function and the user input variable to compare the two functionality in the script. Here we used 1..100 in the variable @demo; it will be called in the unshift(@demo, pop(@demo)) method for comparing the same variable values for the different purposes.

Example #3 use strict; use warnings; print "Welcome User after using the split() function in pop() out the result is: n $varn"; my $var1 = ['55gtg', 'fu', 'erhgfb', 'jwehg', 'jehwgfvj']; pop @$var1; print "Have a Nice day user after popped out the elements from the array list is: @{$var1}n"

Output:

Conclusion

In concluded part, the Perl script used a lot of default methods with their properties in the application. Likewise, pop() is one of the pretty functionality for the data structure using the Perl script. Using these functions, we will remove the last element from the data structure and reduce the memory.

Recommended Articles

This is a guide to Perl pop. Here we discuss the introduction; how does pop function work in Perl? and examples, respectively. You may also have a look at the following articles to learn more –

You're reading How Does Pop Function Work In Perl With Examples

How Does Substring Work In Scala With Examples?

Introduction to Scala Substring

As the name suggests, a scala substring is used to get the substring from the given input. We can find out the substring by specifying any index. Substring function can be call on any string. But have to pass the index in order to use the substring method in Scala. There may be some requirement where we need to find the substring present inside the string input itself so we can go with the substring method in scala. We have two types of methods available in scala to get the substring from the given string. In the coming section, we will discuss more about this method in detail.

Start Your Free Software Development Course

Syntax

As substring string is a method available in scala used to get the substring from the specified index, Let’s see its syntax for better understanding of it and how to use this method on programming see below;

substring(int index)

As we can see in the above syntax, this method takes one parameter as the input type. We can call this method on any String input. Let’s see one practice syntax to understand its real usage see below;

val demostr  = "some string here" demostr.substring(3) How does substring work in Scala?

As of now, we know that the substring method is used to get the string from the string in scala. It is an in build method available in scala, so we can directly use this without being involved in any library in our program. But we can find out the string by mentioning the index while using this method. This method takes one parameter as the input. We have two substring method available in scala based on the input parameter we pass. Now we will see each of them in details about the method signature and its return type; for more understanding, see below;

Method signature

1. String substring(int begningIndex): This is the method signature of substring function as per the scala doc. In this method, we are passing one parameter as the input here. Let’s discuss the input param in detail see below;

int begningIndex: This parameter is used to specify the index of the substring that needs to get from the string input. This is the beginning index of the substring so that it will return the string at the end of the input string from the beginning index. For instance, we can see one example to for better understanding see below;

Example:

object Main extends App{ val str = "hellotoallbye".substring(10) println(str) }

In the above code lines, we create one string named ‘str’ followed by calling the substring method on it. But here, we are passing ’10’ as the starting index for the substring. So it will start from 10 and return us the result at the end of the string. Here we are not mentioning any end index.

2. String substring(int begningIndex, int endIndex): In this method, we are passing two input parameter, and this method is also used to get the substring from the given string input. Only the method signature is different; we can call it method overloading in terms of object-oriented programming language. Let’s discuss each of the parameters in details for better understanding see below;

int begningIndex: This parameter issued to assign the value which will act as the starting point of the substring method in scala. It will work in the same way as before without any difference.

int endIndex: This parameter issued to specify the end index for the substring. Which means it will return the substring at this end index only. This index will act as the ending point for the substring where our substring will end and complete. We will see one practice example of how to use this method while programming see below;

object Main extends App{ val str = "hellotoallbye".substring(8, 10) println(str) }

As you can see in the above lines of code, we are creating one string here and calling the substring method, but this time it will return as the string between the specified index only. This will act as the starting and endpoint of the substring here.

3. return type: Scala’s substring method always returns a new string between the specified index of the given string.

Examples

Here are the following examples of Scala Substring mention below:

Example #1

In this example, we are calculating the string from the beginning index only using substring in scala.

Code:

object Main extends App{ val str1 = "i am string one as input" val str2 = "i am string two as input" val str3 = "i am string three as input" val str4 = "i am string four as input" val str5 = "i am string five as input" val result1 = str1.substring(13) val result2 = str2.substring(11) val result3 = str3.substring(2) val result4 = str4.substring(5) val result5 = str5.substring(15) println("Result one is  :: " ) println(result1) println("Result two is  :: " ) println(result2) println("Result three is  :: " ) println(result3) println("Result four is  :: " ) println(result4) println("Result five is  :: " ) println(result5) }

Output:

Example #2

In this example, we are using the start and end index to get the substring using the substring in scala.

Code:

object Main extends App{ val str1 = "i am string one as input" val str2 = "i am string two as input" val str3 = "i am string three as input" val str4 = "i am string four as input" val str5 = "i am string five as input" val result1 = str1.substring(12, 16) val result2 = str2.substring(12, 16) val result3 = str3.substring(12, 16) val result4 = str4.substring(12, 16) val result5 = str5.substring(12, 16) println("Result one is  :: " ) println(result1) println("Result two is  :: " ) println(result2) println("Result three is  :: " ) println(result3) println("Result four is  :: " ) println(result4) println("Result five is  :: " ) println(result5) }

Output:

Conclusion

By the use of it, we can get the substring from the given string. It will always return us a new string. Also, it is the build method available in scala, so it is easy to use and readable like any other programming language like java.

Recommended Articles

We hope that this EDUCBA information on “Scala Substring” was beneficial to you. You can view EDUCBA’s recommended articles for more information.

How Does React Fragment Work With Examples

Introduction to React Fragment

React Fragments were first launched in the version React 16.2.0. These are used where, earlier, the developers used wrapper div as React Fragments help us group a set of children without adding additional nodes to the DOM. Earlier, the elements were wrapped in a div for returning multiple aspects. This led to some irrelevant markup or rendering of irrelevant HTML, which could have been better for the website. React Fragments solved this problem. This easily returns multiple elements without the need for a wrapper div. This article will explain how to use this with some examples.

Start Your Free Software Development Course

Web development, programming languages, Software testing & others

Syntax:

render() { return ( ); } How does React Fragment work with Examples? 1. Short Example

Components inside src folder:

index.js

style.css

chúng tôi

import React from 'react' import ReactDOM from 'react-dom' function App() { return ( ) }

chúng tôi

.App { font-family: 'Times New Roman', Times, serif, sans-serif; text-align: center; }

Output:

2. Basic

Components inside src folder:

chúng tôi

import React , { Component , Fragment } from "react"; import { render } from "react-dom"; class Columns extends Component { render() { const heros = [ { name: 'Dr. Strange', id: 1 }, { name: 'Ironman', id: 2 }, { name: 'Rocket', id: 3 } ]; return ( <Fragment key={hero.id {hero.name } is SUPER AMAZING!!.... ))} ); } } class Table extends Component { render() { return ( ); } }

Output:

3. With SignIn and SignOut buttons

Components inside src folder:

config folder

admin.js

home.js

login.js

index.js

Components inside config folder:

switch.js

routes.js

chúng tôi

import { Switch } from "react-router-dom"; import React , { Fragment } from "react"; export default function FragmentSupportingSwitch({ children }) { const flattenedChildren = []; flatten(flattenedChildren, children); return React.createElement.apply( React, [Switch, null].concat(flattenedChildren) ); } function flatten(target, children) { if (React.isValidElement(child)) { if (child.type === Fragment) { flatten(target, child.props.children); } else { target.push(child); } } }); }

chúng tôi

import React , { Fragment } from "react"; import { Router , Route } from "react-router-dom"; import Switch from "./Switch"; import createBrowserHistory from "history/createBrowserHistory"; import Login from "../Login"; import Home from "../Home"; import Admin from "../Admin"; export const history = createBrowserHistory(); return ( {!isLoggedIn && ( )} ) : ( <Route exact path="/admin" )} ); }; export default Routes;

chúng tôi

import React from "react"; ); import React from "react"; import { Link } from "react-router-dom"; );

chúng tôi

import React from "react"; );

chúng tôi

import React from "react"; import { render } from "react-dom"; import Routes from "./config/routes"; class App extends React.Component { state = { isLoggedIn: false }; this.setState({ isLoggedIn: true }); }; this.setState({ isLoggedIn: false }); }; render() { return ( <Routes login={this.login} logout={this.logout} isLoggedIn={this.state.isLoggedIn} ); } }

Output:

4. With Switch

Components inside src folder:

chúng tôi

import React from "react"; import ReactDOM from "react-dom"; import { Switch as BaseSwitch , Route , BrowserRouter , Link } from "react-router-dom"; import flattenChildren from "react-flatten-children"; ); class App extends React.Component { state = { private: false }; render() { return ( <button type="button" > {this.state.private ? "Sign Out" : "Sign In"} {this.state.private && ( )} {this.state.private && ( )} ); } } const rootElement = document.getElementById("root");

Output:

5. With Render Fragment

Files to develop this:

fragment.js

Hello.js

index.html

index.js

chúng tôi

import React from 'react'; import PropTypes from 'prop-types'; const [reactMajorVersion] = React.version.split('.'); Wrapper : React.Children.toArray(children) ); if (process.env.NODE_ENV !== 'production') { RenderArrayOrDiv.propTypes = { as: PropTypes.oneOfType([PropTypes.string, PropTypes.func]), children: PropTypes.node.isRequired, }; } RenderArrayOrDiv.defaultProps = { as: canReturnArray ? undefined : 'div', }; console.log(React.Fragment); const Fragment = React.Fragment ? React.Fragment : RenderArrayOrDiv; console.log(Fragment); export default Fragment;

chúng tôi

import React from 'react';

index.html

chúng tôi

import React from 'react'; import { render } from 'react-dom'; import Fragment from 'render-fragment'; import Hello from './Hello'; );

Output:

Conclusion

In this article, we understood This and why it is so helpful to the developers. We went through five different examples to understand the different ways to use this same. This is easy to use, and I hope this article would have explained the ways to use it in a simple and meaningful way.

Recommended Articles

We hope that this EDUCBA information on “React Fragment” was beneficial to you. You can view EDUCBA’s recommended articles for more information.

How Does Do While Loop Work In Java With Examples

Introduction to do while loop in Java

Looping in any programming language has been used ever since. Loops and iterations form an essential component of the programming language, Be it Java or Python; One such looping construct is the do-while loop in the language of Java which is also popularly known as a post-incremental loop, i.e. where the looping construct runs for one time for sure and then the condition is matched for it to run the next time and so on. The condition, in this case, is put in the end. In other words, the condition blocks keep on executing continuously unless and until a specific set of conditions is termed as true.

Start Your Free Software Development Course

Web development, programming languages, Software testing & others

do { } while (expression);

The expression which is mentioned right after the while block is used to return a Boolean value, i.e. either a true value or a false value. If either of the values could not be found, then the compiler throws a compile-time error. The do command in this syntax ensures that the code is executed at least once, even when the expression is not executed, or the condition is not checked. The block of statements is the set of statements that are executed inside the do-while looping construct. This consists of the program body. The while statement, in the end, is used to evaluate the expression and then apply a postcondition to check whether the intended case is meeting the requirements and should be further looped.

How does a do-while loop work in Java?

Following is the explanation for how does do-while loop work in Java:

For a do-while loop to work, the condition is not necessary to be met as this loop also works well for the first time even when the condition is not met. The compiler executor then enters the function execution block executes whatever is there within the block of statements, and then comes out to check the expression part where the condition is compared. If the condition is met, then the loop is reiterated; otherwise, the loop is exited from the block. The basic difference between the while and the do-while loop is that while the former one looks for the pre-conditions, the latter one targets the postconditions.

The basic difference between a do-while and a very well-known loop is that the number of iterations is needed to be known in the loop and the initial value and the value which is being incremented. This is more often used when the iterations and their count are fixed in number, whereas in the case of the do-while loop, the number of iterations is not known before-hand but can change dynamically.

Flow Diagram:

Examples for do-while loop in Java

Below are the examples of all the numbers till 10:

Example #1

Printing all the Numbers less than equal to 10.

Code:

public class Main { public static void main(String args []) { int c=1; System.out.println("printing all the numbers till 10:"); do { System.out.println(c); ++c; } while(c<11); } }

Output:

Example #2

Iterating an Array by making use of do-while loop in Java.

Code:

public class Main { public static void main(String args []) { int arr[]= {1, 6, 7, 514, 4, 98}; System.out.println("Printing the list of arrays: "); int i=0; do { System.out.println(arr[i]); ++i; } while (arr[i]<=6); } }

Example #3

Writing a program for an Infinite do-while loop.

Code:

public class Main { public static void main(String[] args) { do { System.out.println("infinite do while loop"); } while(true); } }

Output:

This program will run infinitely until the code block is explicitly broken as the infinite loop hits the condition of the while loop is true, which is a true condition and will always be met. Therefore, these types of loops and programming constructs are not encouraged. They can confuse the compiler and hang your system if it doesn’t contain appropriate RAM and other memory requirements.

Example #4

Printing all the Numbers from 10 till 1 in Reverse order.

Code:

public class Main { public static void main(String args []) { int c=10; System.out.println("Printing all the numbers from 10 till 1"); do { System.out.println(c); --c; } }

Example #5

Printing all the numbers less than Equal to 10 without using the Increment operator.

Code:

public class Main { public static void main(String args []) { int c=1; System.out.println("printing all the numbers till 10"); do { System.out.println(c); c+=1; } while(c<11); } }

Output:

The basic difference between this example and the first example was the use of shorthand operators in this case and the use of a pre-incremental counter in the case of example number 1. Both of them will produce the same result; it is just a matter of your choice of which operator you wish to choose for the do-while loop.

Conclusion

In this post, we saw the basic level of introduction to do while loop. We also saw the working of the do-while loop in detail. We saw the intricacies and the major differences and the do-while loop applications over other looping constructs such as while or for loops. We studied the flowchart of the do-while loop, which helped us in understanding it more deeply. We read about the syntax and a huge list of various examples to understand the do-while loop clear.

Recommended Articles

This is a guide to do while loop in Java. Here we discuss how does do while loop work in Java, with a flow diagram and top 5 examples in it. You can also go through our other related articles to learn more –

How Stdin Works In Perl? With Examples And Advantages

Introduction to Perl STDIN

Syntax:

Below is the parameter description for the syntax as follows:

STDIN: STDIN is stands for standard input which we have used to take input from the user or to take from the keyboard or any input device. The STDIN will read the line entered from the keyboard along with the new line character and special character corresponding with the enter key which we have press after input.

Variable name: We have used any variable name to define STDIN in perl. We have used variable name to declare STDIN in perl. Variable name parameter is very important and useful in perl to declare value of STDIN variable. We have defined any name to the variable that we have used with STDIN in perl.

How STDIN works in Perl?

The STDIN will read the line entered from the keyboard along with the new line character and special character corresponding with the enter key which we have pressed after input.

STDIN stands for standard input which we have used to take input from the user or to take from the keyboard or any input device.

We can use it with the list context in perl. While using it with list of context it will take multiple value as input from the user.

After pressing enter it will identify that it would be individual elements in the list. We can press ctrl+D in Linux systems and ctrl+Z in windows system to indicate the end of the inputs.

It is very important and useful in perl to get standard input from console or take input from keyboard and any other input device.

It is used to get input from standard console by using it in perl. It is also called as standard input.

We can use it with the scalar context in perl. Scalar context is an operator in perl which have used with STDIN in perl.

Scalar context operator will read the line which was entered from the keyboard along with the new line character in perl.

Scalar context and list context operator is very useful and important. It is used to take input from the user by using STDIN.

We can declare it with variable name, also we can use any variable name to declare and initialize input.

We have defined any name of the variable that we have used with STDIN in perl. Variable name parameter is very important and useful in perl to declare value of STDIN variable.

Examples

Given below are the examples mentioned:

Example #1

STDIN in perl.

In below example we are getting data from the user using standard input.

Code:

use 5.030; use strict;      ## Use strict and warnings use warnings; say "Enter Name:"; say "Welcome $name_user in perl";

Output:

Example #2

STDIN using scalar context.

Below example shows a scalar context in perl. We are using scalar context operator. Scalar context operator will read the line which was entered from the keyboard along with the new line character in perl.

Code:

print "Enter age of usern"; # Getting age from the user by using age_user variable. # Removes new line from the input by using chomp in perl. chomp $age; print "Age is ", $age_user;

Output:

We have taken input as age from the user. We have removed new line character by using chomp. Chomp function removes the new line character from the code.

Example #3

Below example shows STDIN with a list context in perl. We are using list context operator.

Code:

# Get name from the user print "Enter name"; # Removes new line appended using chomp in perl. chomp @user_name; # Print the name of the user. print "nUser name is: [email protected]_name ";

Output:

Advantages

STDIN is used to take input from the user or any input device.

It is very useful and important in perl to take input from the keyboard or from the user.

We can get input from the standard console by using STDIN in perl.

We can take input of scalar and list context operator by using it.

Conclusion

STDIN stands for standard input and abbreviated the name as &lt;STDIN&gt;. The STDIN will read the line entered from the keyboard along with the new line character and special character corresponding with the enter key which we have pressed after input. It is very useful in perl.

Recommended Articles

We hope that this EDUCBA information on “Perl STDIN” was beneficial to you. You can view EDUCBA’s recommended articles for more information.

How The Opendir Function Works In Perl?

Introduction to Perl opendir

Web development, programming languages, Software testing & others

Syntax

As we have seen that opendir is a function that is used to handle operations on the directory in Perl. We have different functions available to operate on the directory. Let’s see the syntax for a better understanding of this function in detail see below;

opendir DIRHANDLE, EXPR

This is the basic syntax for the opendir function as per the Perl documentation. Here we have two parameters as the input. One is the directory handle, and another one is expression. Let’s see one practice syntax for better understanding of the function see below;

opendir(DIR, 'Your_directory_name_here') or die;

In the coming section, we will see in more detail how we can use this while programming in Perl.

How opendir function works in Perl?

As of now, we know that opendir function is used to open the directory in the Perl. In Perl programming language, we have different functions available which are used to handle operations on the directory. If we want to open a directory in Perl, then we can use this function by specifying the directory path there. Let’s see the method signature of this function we have in Perl see below;

Method signature:

opendir (DIR, $directory) or die;

Example:

#!/usr/bin/perl my $mysample = '/your/path/to/directory. ..'; opendir (DIR, $mysample) or die "Error occured, $!"; while ($myfile = readdir DIR) { }

As you can see in the above lines of code, we are using the opendir function to open the directory in Perl and to read the files; we have the readdir function available in Perl. So first, we are creating one variable which is pointing to the directory path that we actually want to read named as ‘my sample’ After this, we are calling the opendir function to perform operations on the directory. Inside this function, we are passing two-parameter as the input. The first parameter is the directory handle which will handle the output And the second parameter is the directory path of the system. After this, we would have all the results in the DIR first parameter; we can read our directory or files in the current directory pointer by the use of it. So we are using the readdir function from the Perl directory to read the directory result inside the loop; we can have our logic to read them. In this way, we are using the opendir function in Perl; by the use of it, we can open the directory and read the files.

If we talk about the return type, we have a below-mentioned point for this function in Perl :

return type: This function return a Boolean value as a result; if successful, it will return true. In case of failure, it will return false as the value.

Points to remember while working with opendir function in Perl:

This function is used to open the directory.

That means we can now access the files or sun directories that are available inside the current search directory.

This is an alternate way to access the directory information and other stiff through Perl programming; this will help us to read the files from code in Perl.

We can also return some error message if the function does not find the mentioned path. We can use one keyword named ‘die’; this can be used to throw or return some error message that the user can easily understand.

If the mentioned directory is not found and even we are also not throwing any error using ‘die’, then it will throw an exception at runtime saying ‘No such file or directory found’.

To read and close the directory, we can use readdir and closedir functions from the Perl directory library.

After successfully reading and opening the directory, we have to close the directory; otherwise, it will lead to some memory leakage.

Examples

Example:

#!/usr/bin/perl my $mydirectory = 'C:/project'; opendir (DIR, $mydirectory) or die "error while finding directory path in system, $!"; while ($myfiledemo = readdir DIR) { print "file name is ::n" print "$myfiledemon"; }

Output:

Conclusion

Opendir function is used to perform operations on the directory in Perl. We can open the directory and access the files inside it using programming by the use of this. This makes the operations on the directory easy to handle; we have so many different functions available to read, close the directory as needed.

Recommended Articles

This is a guide to Perl opendir. Here we discuss How the opendir function works in Perl and Examples along with the outputs. You may also look at the following articles to learn more –

Update the detailed information about How Does Pop Function Work In Perl With Examples on the Daihoichemgio.com website. We hope the article's content will meet your needs, and we will regularly update the information to provide you with the fastest and most accurate information. Have a great day!