The maximum file size is 47 MB. Valid file types are: 8bf, abf, abr, act, aep, afm, ai, arw, as, ase, avi, bmp, book, cel, cfc, chproj, cptx, cr2, cr3, crf, crw, css, csv, dn, dng, doc, docx, eps, epub, exif, fbx, fla, flac, flv, fm, gif, icma, icml, ico, ics, idml, indd, jpeg, jpg, jsfl, json, log, loss, lrcat, lrtemplate, m4a, mif, mov, mp3, mp4, mpg, nef, nrw, obj, odt, orf, otc, otf, pdf, pfb, pfm, pmd, png, ppj, ppt, pptx, prc, prel, prproj, ps, psb, psd, raf, raw, rtf, sbs, sbsar, sbsm, scc, ses, sesx, skp, sol, srt, srw, ssa, stl, svg, swf, tif, ttc, ttf, txt, wav, wmv, x3f, xd, xls, xlsx, xml, xmp.
Are you sure you want to proceed? The operating system keeps track of the default printer and identifies that printer to the various programs on the computer. This allows the programs to pass an extra parameter to the print API telling it to print directly to the default printer without displaying the print dialog first.
Many programs have two different print options - a menu entry that displays the print dialog and a toolbar fast print button that sends directly to the default printer. When you have a web page on the internet that your visitors are going to print, you have next to no information about what printer s they have available.
Most printers around the world are configured to print out on A4 paper but you can't guarantee that the printer is set up to that default. One North American country uses a non-standard paper size that is shorter and wider than A4. Most printers are set up to print out in portrait mode where the narrower direction is the width but some may be set to the landscape where the longer dimension is the width.
Of course, each and every printer also has different default margins at the top, bottom, and sides of the page even before the owners go in and change all of the settings to get the printer the way that they want. Given all of these factors, you have no way to tell whether the default printer with its default configuration will print out your web page on A3 with negligible margins or on A5 with huge margins leaving little more than a postage stamp sized area in the middle of the page.
Since printers vary so much between your potential visitors did someone mention laser printers, inkjet printers, color or black and white only, photo quality, draft mode, and lots more you have no way to tell what they will need to do to print out your page in a reasonable format. Next, comes the matter of what they may want to print. Do they want the whole page or have they selected just a part of the page that they want to print? If your site uses frames do they want to print all of the frames the way they appear on the page, do they want to print each frame separately, or do they just want to print a specific frame?
The need to answer all of these questions makes it just about essential that the print dialog appears whenever they want to print something so that they can make sure that the settings are all correct before they hit the print button.
Most browsers also provide the ability to add a "fast print" button to one of the browser toolbars to allow the page to be printed to the default printer using default browser settings as to what is to be printed and how. Browsers do not make this multitude of browser and printer settings available to Javascript.
Javascript is primarily concerned with modifying the current web page and so web browsers provide minimal information about the browser itself and next to no information about the operating system available to Javascript because Javascript doesn't need to know those things to perform those things that Javascript is intended to do. Basic security says that if something like Javascript doesn't need to know about the operating system and browser configuration in order to manipulate the web page then it should not be provided with that information.
It is not like Javascript ought to be able to change the printer settings to appropriate values for printing the current page because that is not what Javascript is for - that is the job of the print dialog.
Browsers therefore only make available to Javascript those things that Javascript needs to know such as the size of the screen, the available space in the browser window to display the page, and similar things which help Javascript work out how the page is laid out.
The current web page is Javascript's one and only concern. Intranets are of course an entirely different matter. With an intranet, you know that everyone accessing the page is using a specific browser usually a recent version of Internet Explorer and has a specific screen resolution and access to specific printers. For the output, you have the following options:. Loops are part of most programming languages. They allow you to execute blocks of code desired number of times with different values:.
These types of statements are easy to understand. Using them, you can set conditions for when your code is executed. If certain conditions apply, something is done, if not — something else is executed.
A similar concept to if else is the switch statement. However, using the switch you select one of several code blocks to execute. Strings are what JavaScript calls to text that does not perform a function but can appear on the screen. In JavaScript, strings are marked with single or double-quotes. If you want to use quotation marks in a string, you need to use special characters:. Regular expressions are search patterns used to match character combinations in strings.
The search pattern can be used for text search and text to replace operations. You can also work with and modify dates and time with JavaScript. This is the next chapter in the JavaScript cheat sheet. It is the code of the structure of a webpage.
Besides HTML elements, JavaScript is also able to take into account the user browser and incorporate its properties into the code. Events are things that can happen to HTML elements and are performed by the user. The programming language can listen for these events and trigger actions in the code. No JavaScript cheat sheet would be complete without them. When working with JavaScript, different errors can occur. There are several ways of handling them:.
JavaScript is gaining much importance as a programming language.
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