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web-development interview questions

Top web-development frequently asked interview questions

How can I make Chrome stop caching redirects?

I am working on a web application that is using redirects (for pretty URLs).

I am trying to debug logic in the way the redirects are working. However Google Chrome keeps remembering the redirects and even after I change the code, redirecting the same way.

This is making it very hard to troubleshoot.

For example if I redirect /this to /that, then change my code to NOT redirect /this anymore. Google Chrome is still redirecting to /that. Like the redirect is cached or something. Is there a way to turn this off?


Source: (StackOverflow)

How to install Eclipse Web Tools on Eclipse Classic?

I'm using eclipse 3.5.2 classic, and I'd like to install Eclipse Web Tools, but I can't find a url for which to install it.. can anyone find that? or does it not exist?


Source: (StackOverflow)

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How can I find out with which software a web page was written?

I'd like to know which software was used for the development of the web page from hotel.info. How can I do it? Is there any tool for Firefox that could help me finding out this information?


Source: (StackOverflow)

How to manually install Apache, PHP and MySQL on Windows?

How do I install Apache with PHP support and the MySQL server on Windows without using any ready-to-use packages like WAMPServer or XAMPP ?


Source: (StackOverflow)

How can I tell if a screenshot was made in IE7 or IE8?

I have a screenshot of an IE web browser. My question is, how can I tell whether it's IE 7 or IE8?

I've looked on the net and all the different shots of 7 and 8 look the same.


Source: (StackOverflow)

Looking for HTTP debugging proxy for Mac similar to Fiddler on Windows [closed]

In previous jobs when I've worked on a Windows machine, I've used Fiddler for viewing HTTP transactions and debugging.

I'm specifically looking to monitor the HTTP transactions for an ajax site I'm working on to verify that the site is doing what I expect. Rewriting HTTP (as provided by Fiddler) is a nice-to-have, but not essential.

Can anybody recommend something similar for use on a Mac?


Source: (StackOverflow)

Chrome keyboard shortcut to pause script execution

Is there a keyboard shortcut in Google Chrome which will break script execution? (Equivalent to pressing the || "Pause script execution" button in the Developer Tools Scripts panel.)

I'd like to use the Dev Tools to inspect an element in its mouseover state; the mouseleave code will obviously run if I try to actually click the pause button!


Source: (StackOverflow)

Project Management Tools? [closed]

I'm looking for a better PM tool. Something like http://www.axosoft.com/ontime where it looks more like a e-mail client but preferably web hosted.

Any recommendations?


Source: (StackOverflow)

How can I develop for Safari 6 without buying a mac?

I've always found that just developing in Windows, and using Safari for Windows has been sufficient.

However, Safari 6 has now been released, and I've got at least one user who has contacted me, saying he's experienced problems with one of my sites on his new ipad.

The trouble is that Safari for Windows only goes up to 5.1.7.

Do I have to go out and buy a new mac/ipad/iphone in order to test my code, or is there another way?


Source: (StackOverflow)

Performance issues when using SSD for a developer notebook (WAMP/LAMP stack)?

I'm a web application developer using my notebook as a standalone development environment (WAMP stack). I just switched from a Core2-duo Vista 32 bit notebook with 2Gb RAM and SATA HDD, to an i5-2520M Win7 64 bit with 4Gb RAM and 128 GB SDD (Corsair P3 128).

My initial experience was what I expected, fast boot, quick load of all the applications (Eclipse takes now 5 seconds as opposed to 30s on my old notebook), overall great experience. Then I started to build up my development stack, both as LAMP (using VirtualBox with a debian guest) and WAMP (windows native apache + mysql + php). I wanted to compare those two.

This still all worked great out, then I started to pull in my projects to these stacks. And here came the nasty surprise, one of those projects produced a lot worse response times than on my old notebook (that was true for both the VirtualBox and WAMP stack). Apache, php and mysql configurations were practically identical in all environments. I started to do a lot of benchmarking and profiling, and here is what I've found:

  1. All general benchmarks (Performance Test 7.0, HDTune Pro, wPrime2 and some more) gave a big advantage to the new notebook. Nothing surprising here. Disc specific tests showed that read/write operations peaked around 380M/160M for the SSD, and all the different sized block operations also performed very well.

  2. Started apache performance benchmarking with Apache Benchmark for a small static html file (10 concurrent threads, 500 iterations).

    • Old notebook: min 47ms, median 111ms, max 156ms
    • New WAMP stack: min 71ms, median 135ms, max 296ms
    • New LAMP stack (in VirtualBox): min 6ms, median 46ms, max 175ms

    Right here I don't get why the native WAMP stack performed so bad, but at least the LAMP environment brought the expected speed.

  3. Apache performance measurement for non-cached php content. The php runs a loop of 1000 and generates sha1(uniqid()) inisde. Again, 10 concurrent threads, 500 iterations were used for the benchmark.

    • Old notebook: min 0ms, median 39ms, max 218ms
    • New WAMP stack: min 20ms, median 61ms, max 186ms
    • New LAMP stack (in VirtualBox): min 124ms, median 704ms, max 2463ms

    What the hell? The new LAMP performed miserably, and even the new native WAMP was outperformed by the old notebook.

  4. php + mysql test. The test consists of connecting to a database and reading a single record form a table using INNER JOIN on 3 more (indexed) tables, repeated 100 times within a loop. Databases were identical. 10 concurrent threads, 100 iterations were used for the benchmark.

    • Old notebook: min 1201ms, median 1734ms, max 3728ms
    • New WAMP stack: min 367ms, median 675ms, max 1893ms
    • New LAMP stack (in VirtualBox): min 1410ms, median 3659ms, max 5045ms

    And the same test with concurrency set to 1 (instead of 10):

    • Old notebook: min 1201ms, median 1261ms, max 1357ms
    • New WAMP stack: min 399ms, median 483ms, max 539ms
    • New LAMP stack (in VirtualBox): min 285ms, median 348ms, max 444ms

    Strictly for my purposes, as I'm using a self contained development environment (= low concurrency) I could be satisfied with the second test's result. Though I have no idea why the VirtualBox environment performed so bad with higher concurrency.

  5. Finally I performed a test of including many php files. The application that I mentioned at the beginning, the one that was performing so bad, has a heavy bootstrap, loads hundreds of small library and configuration files while initializing. So this test does nothing else just includes about 100 files. Concurrency set to 1, 100 iterations:

    • Old notebook: min 140ms, median 168ms, max 406ms
    • New WAMP stack: min 434ms, median 488ms, max 604ms
    • New LAMP stack (in VirtualBox): min 413ms, median 1040ms, max 1921ms

    Even if I consider that VirtualBox reached those files via shared folders, and that slows things down a bit, I still don't see how could the old notebook outperform so heavily both new configurations. And I think this is the real root of the slow performance, as the application uses even more includes, and the whole bootstrap will occur several times within a page request (for each ajax call, for example).

    To sum it up, here I am with a brand new high-performance notebook that loads the same page in 20 seconds, that my old notebook can do in 5-7 seconds. Needless to say, I'm not a very happy person right now.

    Why do you think I experience these poor performance values? What are my options to remedy this situation?

EDIT: seems like I finally found the root of the problem, apparently SSDs may suffer performance degradation when used in laptops having Intel HM55 or PM55 chipsets. Please see my own full answer below.


Source: (StackOverflow)

How to force Internet Explorer (IE) to REALLY reload the page?

When using Internet Explorer 8 to test my web application I often find it doesn't reload the page, so I don't see my changes. This has resulted in a lot of wasted time and frustration wondering why my fix "didn't work" - when in fact the browser never loaded the fixed version.

I've tried the Refresh button. I've tried F5, Control-F5, Control-R, Control-Shift-R, holding Control while clicking the Refresh button, everything I could think of - it doesn't actually load the new contents from the server. I've confirmed this with Fiddler.

How do I tell IE "I don't care what you think you have cached, I want to reload the page - no really, I mean it this time, honest-to-God, I want you to actually go to the server and download everything again"?


Source: (StackOverflow)

Ruler to measure in browser (firefox)

I'm looking for a good ruler to use to measure distances in a browser. I use Firefox. Any good suggestions that are currently being used by other developers.

I have firebug, but I don't think it has a ruler. Does it? I would think a ruler would have made it to firebug, but there doesn't seem to be one, or I'm not looking in the right location.

Thanks


Source: (StackOverflow)

How do I turn off caching in IIS7?

I'm developing an ASP classic site under Windows 7 (form a queue ladies). The problem is IIS seems to be heavily making use of its cache for both static and dynamic content which really conflicts with my 'make a small change, alt-tab, hit ctrl-F5' development style. Changes made to .asp files may take two or three refreshes to show up where as changes to .js files can take 20 times as many. How do I go about turning the caching off on my development machine?

Cheers.

in b4 stop using asp classic


Source: (StackOverflow)

Filter on request type in chrome dev tools (Network tab)

In previous versions of Chrome I've had a buttom toolbar in which I could filter on different kinds of requests.

It's the one shown here:

enter image description here

I can however not see it anymore. To my knowledge, I've not hidden it but it has disappeared in an update. How can I get it back?


Source: (StackOverflow)

What is the maximum size of a cookie, and how many can be stored in a browser for each web site?

I am learning about cookies, and I wonder about browser support:

  • For each domain/web site, how many cookies may be sent to a browser, and of what size?

  • If multiple cookies are sent and stored, does that affect performance?


Source: (StackOverflow)