var ddDrop = false; var searchMode = "All"; var device = "https://www.sololearn.com/"+(/Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(navigator.userAgent)?"Learn":"Play"); var faq = [ //keywords, title, content, author[optional], links, category /*[["what","html","xhtml","web"],"What is HTML?","HTML XHTML","DanijelMOD",["abc.com"],["All","Programming"]], [["what","java"],"What is Java?","Java is best","C++ SoldierMOD",["http://www.abc.com","xyz.com"],["All","Sololearn"]],*/ [["html","html5","xhtml","htm","web","language","programming"],"What is HTML?","Hypertext Markup Language (HTML) is the standard markup language for creating web pages and web applications. CSS and JavaScript. The w3 consortium is the maintainer of both HTML and CSS. There are many version of HTML language, and the latest version is HTML5. HTML provides a means to create structured documents by denoting structural semantics for text such as headings, paragraphs, lists, links, quotes and other items. HTML elements are delineated by tags, written using angle brackets.","Source: Wikipedia",[device+"/HTML","https://en.wikipedia.org/wiki/HTML"],["All","Programming"]], [["java","language","gosling","android","programming"],"What is Java?","Java is a high level, modern programming language designed in the early 1990s by Sun Microsystems, and currently owned by Oracle. Java is Platform Independent, which means that you only need to write the program once to be able to run it on a number of different platforms! Java is portable, robust, and dynamic, with the ability to fit the needs of virtually any type of application.","",[device+"/Java","https://en.wikipedia.org/wiki/Java_(programming_language)","https://www.java.com/en/","https://www.oracle.com/java/"],["All","Programming"]], [["c++","cpp","language","programming"],"What is C++?","C++ is a general-purpose programming language. It has imperative, object-oriented and generic programming features, while also providing facilities for low-level memory manipulation. It was designed with a bias toward system programming and embedded, resource-constrained and large systems, with performance, efficiency and flexibility of use as its design highlights. C++ has also been found useful in many other contexts, with key strengths being software infrastructure and resource-constrained applications, including desktop applications, servers, and performance-critical applications. C++ is a compiled language, with implementations of it available on many platforms","Source: Wikipedia",[device+"/CPlusPlus","https://en.wikipedia.org/wiki/C%2B%2B","http://www.cplusplus.com/"],["All","Programming"]], [["python","language","programming","data","science"],"What is Python?","Python is an interpreted, high-level, general-purpose programming language. Created by Guido van Rossum and first released in 1991, Python has a design philosophy that emphasizes code readability, notably using significant whitespace. It provides constructs that enable clear programming on both small and large scales. In July 2018, Van Rossum stepped down as the leader in the language community.Python features a dynamic type system and automatic memory management. It supports multiple programming paradigms, including object-oriented, imperative, functional and procedural, and has a large and comprehensive standard library.","Source: Wikipedia",[device+"/Python","https://en.wikipedia.org/wiki/Python_(programming_language)","https://www.python.org/"],["All","Programming"]], [["js","javascript","es6","ecmascript","web","programming","scripting","language"],"What is JavaScript?","JavaScript, often abbreviated as JS, is a high-level, interpreted programming language that conforms to the ECMAScript specification. It is a language that is also characterized as dynamic, weakly typed, prototype-based and multi-paradigm. Alongside HTML and CSS, JavaScript is one of the three core technologies of the World Wide Web.[9] JavaScript enables interactive web pages and thus is an essential part of web applications. The vast majority of websites use it, and all major web browsers have a dedicated JavaScript engine to execute it. As a multi-paradigm language, JavaScript supports event-driven, functional, and imperative (including object-oriented and prototype-based) programming styles. ","Source: Wikipedia",[device+"/JavaScript","https://en.wikipedia.org/wiki/JavaScript","https://www.w3schools.com/js/"],["All","Programming"]], [["css","web","style","cascading","sheet","programming"],"What is CSS?","Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language like HTML. CSS is a cornerstone technology of the World Wide Web, alongside HTML and JavaScript. The CSS specifications are maintained by the World Wide Web Consortium (W3C). In addition to HTML, other markup languages support the use of CSS including XHTML, plain XML, SVG, and XUL.","Source: Wikipedia",[device+"/CSS","https://www.w3schools.com/css/default.asp","https://en.wikipedia.org/wiki/Cascading_Style_Sheets"],["All","Programming"]], [["js","jquery","web","programming"],"What is jQuery?","jQuery is a JavaScript library designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, animation, and Ajax. It is free, open-source software using the permissive MIT License. Web analysis indicates that it is the most widely deployed JavaScript library by a large margin","Resource: Wikipedia",[device+"/jQuery","https://jquery.com/","https://www.w3schools.com/jquery/default.asp","https://en.wikipedia.org/wiki/JQuery"],["All","Programming"]], [["php","server","web","programming","language"],"What is PHP?","PHP: Hypertext Preprocessor (PHP) is a free, highly popular, open source scripting language. PHP scripts are executed on the server. It is capable for

Generating dynamic page content
Creating, opening, reading, writing, deleting, and closing files on the server
Collecting form data
Adding, deleting, and modifying information stored in your database
Controlling user-access
encrypting data

PHP has enough power to work at the core of WordPress, the busiest blogging system on the web. It also has the degree of depth required to run Facebook, the web's largest social network!","",[device+"/PHP","https://www.w3schools.com/php/default.asp","http://www.php.net/","https://en.wikipedia.org/wiki/PHP"],["All","Programming"]], [["c#","cs","net",".net","programming","language"],"What is C#","C# is a general-purpose, multi-paradigm programming language encompassing strong typing, imperative, declarative, functional, generic, object-oriented (class-based), and component-oriented programming disciplines. It was developed around 2000 by Microsoft within its .NET framework. C# is one of the programming languages designed for the Common Language Infrastructure.","Source: Wikipedia",[device+"/CSharp","https://docs.microsoft.com/en-us/dotnet/csharp/","https://en.wikipedia.org/wiki/C_Sharp_(programming_language)"],["All","Programming"]], [["c","programming","language","low","level"],"What is C?","C is a general-purpose programming language that has been around for nearly 50 years. C has been used to write everything from operating systems (including Windows and many others) to complex programs like the Python interpreter, Git, Oracle database, and more. The versatility of C is by design. It is a low-level language that relates closely to the way machines work while still being easy to learn. ","",[device+"/C","https://en.wikipedia.org/wiki/C_(programming_language)"],["All","Programming"]], [["ruby","rails","programming","language"],"What is Ruby?","Ruby is a dynamic, object-oriented, general-purpose programming language. It is ranked among the top 10 programming languages worldwide. Much of its growth is attributed to the popularity of software written in Ruby, particularly the Ruby on Rails web framework.","",[device+"/Ruby","https://www.ruby-lang.org/en/","https://en.wikipedia.org/wiki/Ruby_(programming_language)"],["All","Programming"]], [["swift","programming","language"],"What is Swift?","Swift is a general-purpose programming language built using a modern approach to safety, performance, and software design patterns. The goal of the Swift project is to create the best available language for uses ranging from systems programming, to mobile and desktop apps, scaling up to cloud services. Most importantly, Swift is designed to make writing and maintaining correct programs easier for the developer.","Source: Swift.org",[device+"/Swift","https://swift.org/","https://en.wikipedia.org/wiki/Swift_(programming_language)"],["All","Programming"]], [["sql","query","programming","language","server","databse"],"What is SQL?","SQL/\"sequel\"(Structured Query Language) is a domain-specific language used in programming and designed for managing data held in a relational database management system","Source: Wikipedia",[device+"/SQL","https://www.w3schools.com/sql/default.asp","https://en.wikipedia.org/wiki/SQL"],["All","Programming"]], [["what","best","programming","language","better"],"What is the BEST Programming Language ?","Every language has their own PROs and CONs. It is very important to choose a programming language which best suits your career/project. Following image shows a comparison of the popularity among languages (2019)

","",["https://pypl.github.io/PYPL.html","https://www.tiobe.com/tiobe-index/"],["All","Programming"]], [["what","learn","next","programming"],"I have learned X language. What should I learn next?","
What should I learn next? ","Bono",["https://code.sololearn.com/Wukw9beaMo55/?ref=app"],["All","Programming"]], [["sololearn","rules","forum","questions"],"What are the rules in Sololearn Discusstion Section?","

Post only programming-related QUESTIONS and ANSWERS
SEARCH for similar QUESTIONS or ANSWERS before posting
Include relevant TAGS
Follow community RULES

DO NOT

Post spam/advertisement
Use inappropriate language.
Post general discussions and open-ended questions in your feed.

","Yeva",["https://www.sololearn.com/Content-Creation-Guidelines/","https://www.sololearn.com/Discuss/1316935/welcome-to-sololearn-forum/","https://code.sololearn.com/W26q4WtwSP8W/#"],["All","Sololearn"]], [["sololearn","mod","moderator","rules","rules","who","mods"],"Who are moderators and what are their roles?","Moderators are part of a team that welcomes and supports new members, ensures that our Community Guidelines are upheld, and adds to the already rich conversations across the forum. Moderators are key to keeping SoloLearn safe, valuable, and fun for all members.","",["https://code.sololearn.com/WIHav38M8I4F/#html","https://www.sololearn.com/Moderator-Guidelines/"],["All","Sololearn"]], [["language","first","which","start","programming","pro"],"Which language should I start first?","That depends on what you're trying to achieve.For web development: Start with HTML, and then move on to CSS, JavaScript, JQuery, PHP, and SQL. For general application programming: Python, C++, and Ruby; then Java, C#, or Swift, based on the platform you're targeting.","",["https://code.sololearn.com/Wukw9beaMo55/?ref=app"],["All","Programming"]], [["sololearn","free"],"Is sololearn free?","Learning on SoloLearn is completely free. Our apps are available on Android, iOS, and Web. We do have a premium subscription available called SoloLearn PRO. With a SoloLearn PRO subscription, you will have an ad-free experience with access to a more customized experience that includes setting learning goals and access to personalized activity insights. On the social front, you can see who's viewed your profile and who's learning nearby. We add new features regularly to improve the PRO experience further. For now, SoloLearn PRO is available only for Android users. We expect the iOS version to launch in the next month or two.","Sololearn",[],["All","Sololearn"]], [["sololearn","pro","account","upgrade"],"How do I upgrade to the PRO account?","To subscribe to SoloLearn PRO, tap on the right top menu and select SoloLearn PRO. Choose one of the options available (Monthly or Yearly), and follow the instructions. The cost of a Monthly subscription is $4.99/month, and the cost of the Yearly plan is $3.99/month.","Sololearn",[],["All","Sololearn"]], [["sololearn","pro","cancel"],"How do I cancel my PRO subscription?","You can cancel your PRO subscription anytime you want. Just open the app, go to Settings -> Manage subscriptions, and follow the instructions. After cancelling your subscription, you will be able to use SoloLearn PRO for the remaining days that you have already paid for. When your subscription expires, it will not be renewed. Please note that subscription cancellations cannot be undone, though you can always start a new subscription whenever you want. More information can be found on Google Payments' page.","SoloLearn",["https://support.google.com/pay/answer/7644008?visit_id=636729392014701935-856044845&rd=1"],["All","Sololearn"]], [["sololearn","account","active"],"How do I activate my account?","After you successfully sign up, Sololearn will send an email with activation instructions. All you need to do to activate is tap on the activation link.","SoloLearn",[],["All","Sololearn"]], [["sololearn","account","delete","close"],"How can I close my SoloLearn account?","To close your account, please send a request to info@sololearn.com from the email associated with your account. We will then process your request.","Sololearn",["mailto:info@sololearn.com"],["All","Sololearn"]], [["sololearn","xp"],"What are XP Points?","XP stands for eXperience Points. You earn XP by participating in activities and improving your coding skills. These activities include completing a lesson/course, playing challenges, unlocking badges, and so on.","Sololearn",[],["All","Sololearn"]], [["xp","challenges","how","calculted","calculation","sololearn"],"How are XPs calculated in the Challenges?","The XPs you gain/lose are unique to each match. Calculations take the opponents' levels into account. We use a modified version of the Elo rating system to calculate the points for each won/lost challenge. You can learn more about the Elo rating system here: https://en.wikipedia.org/wiki/Elo_rating_system","sololearn",["https://en.wikipedia.org/wiki/Elo_rating_system"],["All","Sololearn"]], [["sololearn","xp","level","up"],"How do you level up on SoloLearn?","It takes a specific number of XP to level up. Check out the table below:

Level	XP Range
1	0-49
2	50-149
3	150-299
4	300-499
5	1000-1999
6	2000-2999
7	2000-2999
8	3000-3999
9	4000-4999
10	5000-6499
11	6500-7999
12	8000-9999
13	10000-12999
14	13000-14999
15	15000-19999
16	20000-99999
17	1000000-499999
18	500000-749999
19	750000-999999
20	1000000 and up

","",[],["All","Sololearn"]], [["sololearn","feedback"],"How can I provide feedback?","Feel free to send all feedback to inf0@sololearn.com. We take our users' feedback very seriously, and make every effort to thoroughly consider every email, review, or question sent.","Sololearn",["mailto:info@sololearn.com"],["All","Sololearn"]], [["programming","increment","decrement","postfix","prefix","difference","confuse"],"What is the difference between postfix and prefix increment/decrement?","Okay, that's a very basic question. You should have cleared that out before started learning programming.
But here's it...
Example for Prefix Operators ...

int x=2; // x is declared value 2
s = ++x; // ++x means the value of x is increased now and s will be equal to 3 now onwards

Example for Postfix Operators...

int x; // x equals 2 now
s = x++; // postfix operator means that here in the line x will use it's original value but now onwards after this line, x's value will be increased to 3. so s=2, but now x=3.

","Aaron Stone",["https://www.sololearn.com/Discuss/846528/?ref=app","https://www.sololearn.com/Discuss/1562989/?ref=app","https://www.sololearn.com/Discuss/407846/?ref=app","https://www.sololearn.com/Discuss/407846/?ref=app","https://www.sololearn.com/Discuss/1204087/?ref=app","https://www.sololearn.com/Discuss/1274924/?ref=app"],["All","Programming"]], [["salary","programming","programmer","earn"],"How much can a programmer earn?","This highly depends on many factors (experience, skill, age, sex, location, employer, etc.). If you are good and experienced you can earn up to over 1 million $ working at Microsoft. Or you can be some code monkey earning minimum wage in some poor world country.","Roel",["https://www.payscale.com/","https://www.glassdoor.com/index.htm","https://www.sololearn.com/discuss/1454100/?ref=app","https://www.sololearn.com/discuss/404931/?ref=app","https://www.sololearn.com/discuss/1464302/?ref=app","https://www.sololearn.com/discuss/1516299/?ref=app"],["All","programming"]], [["c++","cpp","using","namespace","std"],"What is the use of 'using namespace std;'","A namespace is a form of scope inC++ that holds its own definitions for variables, functions, etc. For example, both cout and cin , along with some useful tokens like endl , are defined inside of std for use.","Vishnu",["https://www.sololearn.com/Discuss/1518433/what-is-the-use-of-using-namespace-std-in-c","http://www.cplusplus.com/forum/beginner/49748/"],["All","Programming"]], [["difference","programming","methods","constructors"],"What is the difference between constructors and methods?","Constructor is internally a nonstatic method with name <init> and voidreturn type. It does not return anything. Internally first object is allocated and then its constructor is called. Object is not allocated with constructor itself.
In other words the syntax new Object()not only calls the constructor but also creates new object and after calling the constructor returns it. The Suns' Java tutorial stands that \"The new operator is followed by a call to a constructor, which initializes the new object.\" Initialize does not mean create.","D_Stark",["https://www.sololearn.com/Discuss/45630/?ref=app","https://www.sololearn.com/Discuss/1653813/?ref=app","https://www.sololearn.com/Discuss/463342/?ref=app"],["All","Programming"]], [["programming","responsive","web","design"],"What is responsive web designing and how to achieve it?","It means that a website/web application adjusts element dimensions to suit the screen size of the device it is being viewed on.
If you're completely new, learn css media queries. When comfortable with basic web fundamentals then consider using something like bootstrap, jQuery ui or react. There are many frameworks you can use to speed up development and ensure your project is adaptable (responsive) to any device.","MikeM",["https://en.m.wikipedia.org/wiki/Responsive_web_design","https://www.sololearn.com/Discuss/1436355/ref=app"," https://www.w3schools.com/css/css_rwd_intro.asp","https://alistapart.com/article/responsive-web-design","https://www.sololearn.com/Discuss/696038/?ref=app","https://www.sololearn.com/Discuss/1456054/?ref=app"],["All","Programming"]], [["programming","difference","inline","block","elements","html"],"What is the differece between block and inline elements in HTML?","Block-level Elements

If no width is set, will expand naturally to fill its parent container
Can have margins and/or padding
If no height is set, will expand naturally to fit its child elements (assuming they are not floated or positioned)
By default, will be placed below previous elements in the markup (assuming no floats or positioning on surrounding elements)
Ignores the vertical-align property
It's also not necessary to “clear” a block element; assuming no floats are affecting the block element, it will be cleared automatically and will start on the next “line” in the page’s output.

Examples

<p>, <div>, <form>, <header>, <nav>, <ul>, <li>, and <h1>.

Inline Elements

Flows along with text content, thus Will not clear previous content to drop to the next line like block elements
Is subject to white-space settings in CSS
Will ignore top and bottom margin settings, but will apply left and right margins, and any padding
Will ignore the width and height properties
If floated left or right, will automatically become a block-level element, subject to all block characteristics
Is subject to the vertical-align property

The easiest way to picture an inline element is to think of it as a box that acts like text. What happens, for example, to text that’s not separated by other elements? It flows one letter after the other. If you put an inline element next to text, it will flow next to that text just like another piece of text.
Examples

<a>, <span>, <b>, <em>, <i>, <cite>, <mark>, and <code>.

","Shudarshan Rai 👑",["https://www.sololearn.com/Discuss/1119207/?ref=app","https://www.w3schools.com/html/html_blocks.asp","https://developer.mozilla.org/en-US/docs/Web/HTML/Inline_elements","https://www.sololearn.com/discuss/454647/?ref=app","https://www.sololearn.com/discuss/346549/?ref=app","https://www.sololearn.com/discuss/1028674/?ref=app"],["All","Programming"]], [["python","programming","difference","lists","tuples","dictionaries","list","tuple","dictionary"],"What are the differences between Python list, tuples and dictionaries?","All are collection types.

Lists are collections of values of any type (like integers, strings, other lists, object, etc.) - they are indexed from 0 to x, where x equals the list's length minus 1. Lists are mutable, sliceable, expandable and replaceable.

Tuples are very similar to lists with an exception that they are immutable. Once created, a tuple cannot be changed (a very important feature which may be beneficial rather than disadvantageous).

Dictionaries are collections of key-value pairs, where keys are unique and has to be of an immutable type (it can be an integer, a string or a tuple for example). Dictionaries themselves are mutable (changeable), expandable and you can call their indexes. But, they are not ordered, which means you can't be sure of an order of iteration, for example.","Kuba Siekierzyński",["https://www.sololearn.com/Discuss/1521094/?ref=app","https://www.sololearn.com/Discuss/679265/?ref=app","https://www.sololearn.com/Discuss/453130/?ref=app","https://www.sololearn.com/Discuss/453130/?ref=app"],["All","Programming"]], ]; $(document).ready(()=>{ $("#searchBar").change(()=>{ search( $("#searchBar").val(),searchMode ) ; }); $("#ddl").hide(); search(" "); $("#_Search").click(()=>{ search($("#searchBar").val(),searchMode); }); $("#all").click(()=>{ searchMode = "All"; search($("#searchBar").val()); ddDrop = !ddDrop; $("#ddb").html(searchMode+" "+(ddDrop?"":"")); $("#ddl").slideToggle(); }); $("#sl").click(()=>{ searchMode = "Sololearn"; search($("#searchBar").val(),"Sololearn"); ddDrop = !ddDrop; $("#ddb").html(searchMode+" "+(ddDrop?"":"")); $("#ddl").slideToggle(); }); $("#program").click(()=>{ searchMode = "Programming"; search($("#searchBar").val(),"Programming"); ddDrop = !ddDrop; $("#ddb").html(searchMode+" "+(ddDrop?"":"")); $("#ddl").slideToggle(); }); $("#ddb").click(()=>{ $("#ddl").slideToggle(); ddDrop = !ddDrop; $("#ddb").html(searchMode+" "+(ddDrop?"":"")); }); }); function search(q,sort="All") { let start = Date.now(); let results = 0; if(q.replace(" ","")==="") { $("#res").html(""); for(let r of faq) { if(r[5].includes(sort)) { $("#res").append("

"+r[1]+"

"+r[2]+"
- "+r[3]+" -
Related Links: "+r[4].map(x=>"
"+x+"").toString().replace(/,/g,"")+"

"); results++; } } $("#searchInfo").html("Found "+results+" results in "+(Date.now()-start)+"ms"); return 0; } let resArr = []; q = q.toLowerCase().replace(/\s+/gi," ").split(" "); $("#res").html(""); for(let r of faq) { let score = 0; fss:for(let key=0;key{return b[6]-a[6];}) for(let s of resArr) { $("#res").append("

"+s[1]+"

"+s[2]+"
- "+s[3]+" -
Related Links: "+s[4].map(x=>"
"+x+"").toString().replace(/,/g,"")+"

"); } $("#searchInfo").html("Found "+results+" results in "+(Date.now()-start)+"ms"); } function toggleFaq(event) { //console.log($(event.target).attr("value")); $(event.target).siblings('section').slideToggle(); $(event.target).css({transform:$(event.target).attr("value")=="false"?"rotate(180deg)":"rotate(0deg)" ,transition: "all linear .4s"}); $(event.target).attr("value",$(event.target).attr("value")=="false"?"true":"false"); }

Sololearn FAQ