PHP-and-MySQL/C2/Common-Errors-Part-3/English-timed
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Revision as of 11:49, 10 July 2014 by Pratik kamble (Talk | contribs)
Time | Narration |
00:00 | Right now I am onto the last two common errors that I have included. |
00:05 | And we will start with the hard one. |
00:09 | This is php header and we are using "header" function going to a location. |
00:14 | And here I have got some html code. |
00:18 | This is a header tag, I am saying "Welcome!". |
00:21 | And our "goto" variable is "google dot com". |
00:26 | If the "goto" exists, which it currently does, we are going to redirect the page to a u-r-l "google dot com". |
00:35 | Right now, this will return an error. |
00:37 | And the error is - Oh! um... Okay that’s why. "o b start". |
00:50 | Lets get rid of this. That wasn’t supposed to be there. That code is to fix the error! |
00:56 | Sorry, so we will go to "php header" and we have got "Welcome!" - our html code. |
01:03 | Then a warning - "Cannot modify header information – headers already sent by..." and all of this. |
01:10 | Okay so our headers have already been sent. This is the line no. by the way. |
01:16 | 1, 2, 3 so if it gives you an error like "phpheader dot php" colon 3, then the error has occurred on the line no. 3. |
01:26 | So that's where the error is - on line 3, okay? |
01:32 | And this error has been generated by line 9, which if you go here, is our "header" function. |
01:39 | So the reason that this is happening is we are already sending our html code. |
01:47 | If I get rid of this by commenting it, and I were to refresh then we would be redirected to google. |
01:54 | But the point is that we want this welcome header here. |
01:59 | And you can’t actually put html before a header function, going to location and other features of this function. |
02:10 | You shouldn't do so. |
02:15 | So as you saw a minute ago that is "ob underscore start". |
02:20 | What this does is, it fixes this problem for us. |
02:25 | So I can come here to "phpheader" and it works, even though I have still got my html code echoed here before my header. |
02:37 | So without this we get an error (pause) and with this our header works fine, okay? |
02:47 | Despite the initial rule of no html output before header up here. |
02:53 | That should be pretty clear by now. |
02:55 | Now, the last one is extremely simple. |
02:58 | I don’t even need to explain it but anyway. |
03:02 | This is "include a file which doesn’t even exist" named as "idontexist dot php". |
03:08 | So lets have a look. Um.. where is it? "missing dot php". |
03:13 | Oh no! Its not. "open dot php". |
03:16 | Okay! So - include "idontexist dot php" failed to open stream; no such file or directory in that name here. |
03:25 | Our file name and directory on line 3. |
03:27 | So lets come to line 3. |
03:30 | And that is the only line of significant code in this file. |
03:35 | We have another warning here - Failed to open "idontexist dot php" for inclusion and all of this. So we get two errors. |
03:43 | This is quite messy when you have a page that has "include a header file". |
03:50 | Then these don’t look too nice. I mean you have probably been in a website before and you have seen this at the top. |
03:57 | You need to be attractive. So you can put a "@ (at)" symbol in front and refresh. |
04:02 | That won't show the error anymore. |
04:06 | But it doesn’t excuse the fact that the file doesn’t exist. |
04:10 | So the content of the file which doesn’t exist, won’t be included. |
04:14 | But yes, to be honest, looking at this, this is really pretty much self explanatory. I just thought I should explain this anyways. |
04:23 | So we have got a small collection of errors that you might come across when you are programming in php. |
04:30 | If there are other errors that you are getting, then please message me and I will be happy to help. |
04:39 | Please subscribe for latest updates. Thanks for watching. This is Evan Varkey dubbing for the Spoken Tutorial project. |