We can give a value to the 'isString()' and 'isNotString()' tests to determine whether it is a valid string or not. Link to Challenge : https://www.freecodecamp.org/learn/quality-assurance/quality-assurance-and-testing-with-chai/test-if-a-value-is-a-string Written Guide: https://www.notion.so/ganeshh123/Test-if-a-Value-is-a-String-f36aca094d2d4a989df5709673eb7274 Full Playlist for this course : https://www.youtube.com/playlist?list=PLhGp6N0DI_1SVteCORbgwlxJkAbcTiZyj All Writen Guides for this course : https://www.notion.so/ganeshh123/54ecbf7833414db885eec37f580599b4 All My Tutorials can be found at : https://www.notion.so/Tutorials-Ganesh-H-293ea420d34a464f9a1907e0405b5f26 0:00 - Concepts: 0:03 - asset.isString() https://www.chaijs.com/api/assert/#method_isstring 01:14 - assert.isNotString() https://www.chaijs.com/api/assert/#method_isnotstring 01:50 - Challenge Solution -————————————————————————————————————- Chai is an assertion library, similar to Node's built-in assert. It makes testing much easier by giving you lots of assertions you can run against your code. freeCodeCamp (also referred to as “Free Code Camp”) is a non-profit organization that consists of an interactive learning web platform, an online community forum, chat rooms, online publications and local organizations that intend to make learning web development accessible to anyone. Beginning with tutorials that introduce students to HTML, CSS and JavaScript, students progress to project assignments that they complete either alone or in pairs. Upon completion of all project tasks, students are partnered with other nonprofits to build web applications, giving the students practical development experience. Thanks for Watching! ... https://www.youtube.com/watch?v=NjkM9CoRt9g

You can use user-agent switching on chrome from any PC to use all the features of the Instagram mobile app. This also works with Firefox. Written Guide: https://www.notion.so/ganeshh123/Use-Full-Instagram-from-any-PC-Post-photos-stories-and-send-DMs-direct-from-Chrome-7a7c8a66a301417db674ecd4f0422573 ----------------------------------------------------------------------------------------------- Links: Instagram: https://www.instagram.com/ ----------------------------------------------------------------------------------------------- Commands: F12 to quickly enter developer tools ----------------------------------------------------------------------------------------------- Music: Did You Feel It by Dexter Britain : https://dexterbritain.com/ Link: https://dexterbritain.com/portfolio-item/same-old-moments/ --------------------------------------------------------------------------------------------- Thanks for Watching! ... https://www.youtube.com/watch?v=LGXdP0cD_9c

Labels can be added to the SVG circles, with text elements. We can set the x and y coordinates as well as the inner text using callback functions and the attribute method. Link to challenge : https://www.freecodecamp.org/learn/data-visualization/data-visualization-with-d3/add-labels-to-scatter-plot-circles Concepts: selection.text([value]) If a value is specified, sets the text content to the specified value on all selected elements, replacing any existing child elements. If the value is a constant, then all elements are given the same text content; otherwise, if the value is a function, it is evaluated for each selected element, in order, being passed the current datum (d), the current index (i), and the current group (nodes), with this as the current DOM element (nodes[i]). The function’s return value is then used to set each element’s text content. A null value will clear the content. If a value is not specified, returns the text content for the first (non-null) element in the selection. This is generally useful only if you know the selection contains exactly one element. https://github.com/d3/d3-selection/blob/v1.4.1/README.md#selection_text selection.attr(name[, value]) If a value is specified, sets the attribute with the specified name to the specified value on the selected elements and returns this selection. If the value is a constant, all elements are given the same attribute value; otherwise, if the value is a function, it is evaluated for each selected element, in order, being passed the current datum (d), the current index (i), and the current group (nodes), with this as the current DOM element (nodes[i]). The function’s return value is then used to set each element’s attribute. A null value will remove the specified attribute. If a value is not specified, returns the current value of the specified attribute for the first (non-null) element in the selection. This is generally useful only if you know that the selection contains exactly one element. https://github.com/d3/d3-selection/blob/v1.4.1/README.md#selection_attr -————————————————————————————————————- D3.js (also known as D3, short for Data-Driven Documents) is a JavaScript library for producing dynamic, interactive data visualizations in web browsers. It makes use of Scalable Vector Graphics (SVG), HTML5, and Cascading Style Sheets (CSS) standards. freeCodeCamp (also referred to as “Free Code Camp”) is a non-profit organization that consists of an interactive learning web platform, an online community forum, chat rooms, online publications and local organizations that intend to make learning web development accessible to anyone. Beginning with tutorials that introduce students to HTML, CSS and J ... https://www.youtube.com/watch?v=dR_nk1rPv7Q

IMPORTANT: You must use Helmet version 2.3.0 for this test to pass! Browsers often 'prefetch' DNS records to cache IP addresses of pages you are likely to visit. We look at some potential issues with this and how we can use helmet's dnsPrefetchControl() middleware to set a header to disable this. Link to Challenge : https://www.freecodecamp.org/learn/information-security/information-security-with-helmetjs/disable-dns-prefetching-with-helmet-dnsprefetchcontrol Written Guide: https://www.notion.so/ganeshh123/Disable-DNS-Prefetching-with-helmet-dnsPrefetchControl-e5a969e6ed324ba09c8e00f33148d4fc Full Playlist for this course : https://www.youtube.com/playlist?list=PLhGp6N0DI_1TeEsQOdf1JmV8PnkQfEpQ4 All Writen Guides for this course : https://www.notion.so/ganeshh123/8ba82d9d1ff84c4583d6e9418ebe426b All My Tutorials can be found at : https://www.notion.so/Tutorials-Ganesh-H-293ea420d34a464f9a1907e0405b5f26 00:00 - Introduction 00:09 - What is DNS Prefetching? DNS prefetching is an attempt to resolve domain names before a user tries to follow a link. Once a domain name has been resolved, if the user does navigate to that domain, there will be no effective delay due to DNS resolution time https://www.chromium.org/developers/design-documents/dns-prefetching 00:50 - Advantage of DNS Prefetching 00:58 - Potential Issues with DNS Prefetching 03:07 - Performance vs Security Tradeoff 03:23 - X-DNS-Prefetch-Control Header The X-DNS-Prefetch-Control HTTP response header controls DNS prefetching, a feature by which browsers proactively perform domain name resolution on both links that the user may choose to follow as well as URLs for items referenced by the document, including images, CSS, JavaScript, and so forth. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-DNS-Prefetch-Control 03:38 - Use Helmet version 2.3.0 04:44 - Setting the Header - helmet.dnsPrefetchControl() helmet.dnsPrefetchControl sets the X-DNS-Prefetch-Control header to help control DNS prefetching, which can improve user privacy at the expense of performance. https://github.com/helmetjs/helmet/tree/master/middlewares/x-dns-prefetch-control 05:08 - Testing -————————————————————————————————————- HelmetJS is a type of middleware for Express-based applications that automatically sets HTTP headers to prevent sensitive information from unintentionally being passed between the server and client. While HelmetJS does not account for all situations, it does include support for common ones like Content Security Policy, XSS Filtering, and HTTP Strict Transport Security, among others. HelmetJS can be installed on an Express project from npm, after which each layer of protection can be configured to best fit the project. f ... https://www.youtube.com/watch?v=lbWGMv1FCjc