What Javascript Cannot Do

What Javascript Cannot Do While there are a large number of things that JavaScript can be utilized to upgrade your pages and improve your guests involvement in your site, there are likewise a couple of things that JavaScript cannot do. A portion of these constraints are because of the way that the content is running in the program window and along these lines can't get to the server while others are because of security that is set up to prevent pages from having the option to alter your PC. Its absolutely impossible to work around these restrictions and any individual who professes to have the option to play out any of the accompanying errands utilizing JavaScript has not considered the entirety of the parts of whatever it is that they are attempting to do. It Cannot Write to Files on the Server Without the Help of a Server-Side Script Utilizing Ajax, JavaScript can send a solicitation to the server. This solicitation can peruse a document in XML or plain content configuration however it can't keep in touch with a record except if the document approached the server really runs as a content to do the document compose for you. JavaScript can't get to databases except if you use Ajax and have a server-side content to play out the database gets to for you. It Cannot Read From or Write to Files in the Client Despite the fact that JavaScript is running on the customer PC (the one where the website page is being seen) it isn't permitted to get to anything outside of the page itself. This is accomplished for reasons of security since in any case a site page would have the option to refresh your PC to introduce who realizes what. The main special case to this are records called treats which are little content documents that JavaScript can write to and read from. The program confines access to treats with the goal that a given site page can just access treats made by a similar site. JavaScript can't close a window on the off chance that it didnt open it. Again this is for security reasons. It Cannot Access Web Pages Hosted on Another Domain Despite the fact that site pages from various spaces can be shown simultaneously, either in independent program windows or in discrete edges inside a similar program window, the JavaScript running on a website page having a place with one area can't get to any data about a site page from an alternate area. This assists with guaranteeing that private data about you that might be known to the proprietors of one space isn't imparted to different areas whose site pages you may have open simultaneously. The best way to get to documents from another space is to do an Ajax call to your server and have a server side content access the other area. It Cannot Protect Your Page Source or Images Any pictures on your page are downloaded independently to the PC showing the page so the individual survey the page as of now has a duplicate of the entirety of the pictures when they see the page. The equivalent is valid for the real HTML wellspring of the site page. The site page should have the option to decode any page that is scrambled so as to have the option to show it. While a scrambled website page may require JavaScript to be empowered all together for the page to have the option to be decoded with the end goal for it to have the option to be shown by the internet browser, when the page has been unscrambled any individual who realizes by what method can without much of a stretch spare the decoded duplicate of the page source.