Web Technology Experts Notes

PHP Frequently asked Auestions and Answer 2015

Question: What is PHP?
PHP is a server-side scripting language which is used to create the dynamic web pages.

Question: Who is fater of PHP?
Rasmus Lerdorf

Question: Which language is used to Implementation?
C/C++

Question: What is offical website of PHP?
http://php.net/

Question: What is current statable version of PHP?
Version: 7.0.6 Dated April 29, 2016.

Question: What is extensions of PHP File?
.php, .phtml, .php4, .php3, .php5, .phps

Question: Describe how PHP Works with Browser?
Works in following Flow
1. Open website http://www.web-technology-experts-notes.in/
2. Request send to server of http://www.web-technology-experts-notes.in/
3. Call PHP Files.
4. PHP Scripts are loaded into memory and compiled into Zend opcode.
5. These opcodes are executed and the HTML generated.
6. Same HTML is send back to Browser.

Know more: http://www.web-technology-experts-notes.in/2012/07/what-is-zend-engine-in-php.html

Question: What are important things about php functions?
PHP function start with "function function-name()".
PHP Function name must be start with character and it accept alphanumeric and _.
In build functions are case in-sensitive.
User build functions are case sensitive.
We can pass upto 64 parameter as argument.
Anonymous function are user defined function which have "no-name" and also called closures.
PHP support variable functions. Means when you can call a function using variable.
In same file OR under same class, same function name can't be created.

Question: What is role of htmlentities?
htmlentities is used to convert all applicable characters to HTML entities.
It is used to stop the user from running malicious code in HTML.
With use of htmlentities, user can't run the html tags like h2, p, script etc. It helps to prevent you from XSS attack.

echo htmlentities($userData);

Question: How to use email with PHP?
Email functionality is inbuilt with PHP.
PHP provide mail() with use of this, we can sen an email to user or subscriber.
We can send html/text email.
We can send attachment with email.
We can also use option like cc, bc and bcc.
We can also set the values in header.
We can also use third party API like (gmail, yahoo etc) to send email.

Question: How session and cookie works together?
Create an session in PHP.
Session data is stored in Server.
Session data have unique name.
Session unique key with domain name is stored in browser cookie.
Now, Browser keep the login with use of unique key(in cookie) and session data (stored in server side).

Question: What is the difference between the functions unlink and unset?
unlink: delete the files from Server.
unset: delete the variable name and data from memory.

Question: How to create subdomain?
With use virtual host and htaccess, you can create sub domain.

Question: What are the various methods to pass data from one web page to another web page?
Session
Cookie
Database
URL parameters

Question: What are super global variables?
$_COOKIE – Stored information in Cookie.
$_GET – Send data in URL as paramter.
$_POST – Send data to server OR Page as POST Method.
$_REQUEST – Its combined array containing values from the $_GET, $_POST and $_COOKIES.
$_ENV – Get/Set varaible in environment.
$_FILES – Used to upload the file, image and videos etc.
$_SERVER – It have all server information.
$GLOBALS – Contains all the global variables associated with the current script.

Question: How to get a user's IP address of client.
echo $_SESSION['REMOTE_ADDR'];

Question: What type of inheritance supported by PHP?
Single inheritance.
Multiple Level inheritance.

Question: What is CMS?
CMS means Content Management System. It is web software who provide the website full fledged content management where owner can add/update/delete the html/files/images/videos etc. Today's CMS do much more as compare to its name.
For example. Joomla/Wordpress is CMS but you can create E-commererce website and can accpet all types of payment.
In Today's CMS, you can create many different types of website like Ecommerce website, Personal blogging and Forum etc.

Question: How to create unique random password?
echo md5(uniqid(rand(), true));

Question: What is the difference between echo and print?
echo constructor which is used to display the value in browser.
print is function which is used to display and return the value.

Question: What is the difference between characters \023 and \x23?
\023 is octal 23.
\x23 is hex 23.

Youtube v3 API Sample API Requests and Response - Search Videos - Get Video Details

For youtube v3 API, you must need an API_KEY for video search, get video details, upload video and delete video etc.
In each request, you need to pass the APK_KEY to get the records, If you didn't pass the API_KEY, you will not get the response from youtube api.

In Youtube V2 API_KEY is not required, but its is compulsary for youtube V3 API.
google has stopped the youtube v2 API so you must use V3 API.

If you don't have API_KEY, please get the API Key from http://code.google.com/apis/console#access .
You must need google account for youtube v3 API.

Youtube v3 API Sample API Requests and Response - Search Video List - Get Video Details

Now, I am assuming you have valid API_KEY. if you have added referer while creating API, then you can use API_KEY for that domain only. Yeah you can add multiple domain for 1 key.
Suppose we have following API_KEY.
API_KEY: AIzaSyBqXp0Uo2ktJcMRpL_ZwF5inLTWZfsCYqY

Also you must enable the "YouTube Data API" from google console for the same key.

Get List of youtube Videos (By Default It will gives 4 videos)

https://www.googleapis.com/youtube/v3/search?part=snippet&key=AIzaSyBqXp0Uo2ktJcMRpL_ZwF5inLTWZfsCYqY

Get List of youtube videos (Search 40 videos)

https://www.googleapis.com/youtube/v3/search?part=snippet&maxResults=40&key=AIzaSyBqXp0Uo2ktJcMRpL_ZwF5inLTWZfsCYqY

Get List of youtube videos (Search 40 videos + having keyword "sports" )

https://www.googleapis.com/youtube/v3/search?part=snippet&q=sports&maxResults=40&key=AIzaSyBqXp0Uo2ktJcMRpL_ZwF5inLTWZfsCYqY

Get List of youtube videos( Search with 100km of 37.42307,-122.08427(lat/long)

https://www.googleapis.com/youtube/v3/search?locationRadius=100km&part=snippet&location=37.42307%2C-122.08427&type=video&key=AIzaSyBqXp0Uo2ktJcMRpL_ZwF5inLTWZfsCYqY

Get List of youtube videos (search videos which are tags with sports [videoCategoryId=17])

https://www.googleapis.com/youtube/v3/search?part=snippet&type=video&videoCategoryId=17&key=AIzaSyBqXp0Uo2ktJcMRpL_ZwF5inLTWZfsCYqY

Response Format:

{"kind":"youtube#searchListResponse","etag":"\"tbWC5XrSXxe1WOAx6MK9z4hHSU8/okahf16vRr9O67w1AX2xksAkmDI\"","nextPageToken":"CAUQAA","pageInfo":{"totalResults":1000000,"resultsPerPage":5},"items":[{"kind":"youtube#searchResult","etag":"\"tbWC5XrSXxe1WOAx6MK9z4hHSU8/EIQjGNXfg22wA149MrmBxBM3QX4\"","id":{"kind":"youtube#video","videoId":"a2RA0vsZXf8"},"snippet":{"publishedAt":"2010-11-21T05:14:05.000Z","channelId":"UCplkk3J5wrEl0TNrthHjq4Q","title":"\"Just A Dream\" by Nelly - Sam Tsui & Christina Grimmie","description":"Check out our epic song with Coke Bottles! https://www.youtube.com/watch?v=ZzuRvzsNpTU Hope you guys like this duet between Christina Grimmie and Sam ...","thumbnails":{"default":{"url":"https://i.ytimg.com/vi/a2RA0vsZXf8/default.jpg"},"medium":{"url":"https://i.ytimg.com/vi/a2RA0vsZXf8/mqdefault.jpg"},"high":{"url":"https://i.ytimg.com/vi/a2RA0vsZXf8/hqdefault.jpg"}},"channelTitle":"KurtHugoSchneider","liveBroadcastContent":"none"}},{"kind":"youtube#searchResult","etag":"\"tbWC5XrSXxe1WOAx6MK9z4hHSU8/3bB0h6KJXx-TPbAqXKd5nADWGX0\"","id":{"kind":"youtube#video","videoId":"Ahha3Cqe_fk"},"snippet":{"publishedAt":"2011-11-11T18:37:24.000Z","channelId":"UC-8Q-hLdECwQmaWNwXitYDw","title":"Katy Perry - The One That Got Away","description":"Sometimes you promise someone forever but it doesn't work out that way. Watch Katy Perry and Diego Luna star in the sixth chapter of the “Teenage Dream” ...","thumbnails":{"default":{"url":"https://i.ytimg.com/vi/Ahha3Cqe_fk/default.jpg"},"medium":{"url":"https://i.ytimg.com/vi/Ahha3Cqe_fk/mqdefault.jpg"},"high":{"url":"https://i.ytimg.com/vi/Ahha3Cqe_fk/hqdefault.jpg"}},"channelTitle":"KatyPerryVEVO","liveBroadcastContent":"none"}},{"kind":"youtube#searchResult","etag":"\"tbWC5XrSXxe1WOAx6MK9z4hHSU8/VZLQn8wfLOJ60oe6Bced9ryD7Kg\"","id":{"kind":"youtube#video","videoId":"NV7xJ73_eeM"},"snippet":{"publishedAt":"2014-11-17T14:00:19.000Z","channelId":"UCMu5gPmKp5av0QCAajKTMhw","title":"Romeo and Juliet vs Bonnie and Clyde. Epic Rap Battles of History Season 4","description":"Download on iTunes ▻ http://bit.ly/1yN7aai ◅ Season 3 Autographed CDs available at ▻ http://shop.erb.fm ◅ Subscribe for more battles! http://bit.ly/1ElwJ40 ...","thumbnails":{"default":{"url":"https://i.ytimg.com/vi/NV7xJ73_eeM/default.jpg"},"medium":{"url":"https://i.ytimg.com/vi/NV7xJ73_eeM/mqdefault.jpg"},"high":{"url":"https://i.ytimg.com/vi/NV7xJ73_eeM/hqdefault.jpg"}},"channelTitle":"ERB","liveBroadcastContent":"none"}},{"kind":"youtube#searchResult","etag":"\"tbWC5XrSXxe1WOAx6MK9z4hHSU8/IN61vHPZ3FNoK9mme_Kf9E0U50c\"","id":{"kind":"youtube#video","videoId":"XjwZAa2EjKA"},"snippet":{"publishedAt":"2013-11-20T08:03:53.000Z","channelId":"UC-8Q-hLdECwQmaWNwXitYDw","title":"Katy Perry - Unconditionally (Official)","description":"Download \"Unconditionally\" from Katy Perry's 'PRISM': http://smarturl.it/PRISM Official video for Katy Perry's \"Unconditionally\" directed by Brent Bonacorso and ...","thumbnails":{"default":{"url":"https://i.ytimg.com/vi/XjwZAa2EjKA/default.jpg"},"medium":{"url":"https://i.ytimg.com/vi/XjwZAa2EjKA/mqdefault.jpg"},"high":{"url":"https://i.ytimg.com/vi/XjwZAa2EjKA/hqdefault.jpg"}},"channelTitle":"KatyPerryVEVO","liveBroadcastContent":"none"}},{"kind":"youtube#searchResult","etag":"\"tbWC5XrSXxe1WOAx6MK9z4hHSU8/gKZhz62FdXndZR7dJdi_PDTpe9U\"","id":{"kind":"youtube#video","videoId":"-kWHMH2kxXs"},"snippet":{"publishedAt":"2014-11-01T04:10:36.000Z","channelId":"UC8-Th83bH_thdKZDJCrn88g","title":"Wheel of Impressions with Kevin Spacey","description":"In this Halloween edition of Wheel of Impressions, Jimmy and Kevin take turns doing random celebrity impersonations, such as Christopher Walken talking ...","thumbnails":{"default":{"url":"https://i.ytimg.com/vi/-kWHMH2kxXs/default.jpg"},"medium":{"url":"https://i.ytimg.com/vi/-kWHMH2kxXs/mqdefault.jpg"},"high":{"url":"https://i.ytimg.com/vi/-kWHMH2kxXs/hqdefault.jpg"}},"channelTitle":"latenight","liveBroadcastContent":"none"}}]}

Get Youtube Videos by Channel

https://www.googleapis.com/youtube/v3/search?part=snippet&channelId=UCv7IjJclSgpfGUHnG171ovw&order=date&key=AIzaSyBpu8hgnXbkqFVWrAvwRUEz7T13ii3I7WM

Response Format:

{"kind":"youtube#searchListResponse","etag":"\"tbWC5XrSXxe1WOAx6MK9z4hHSU8/q7tdIBpMwbnE_LWyfCaBtuEXMes\"","nextPageToken":"CAUQAA","pageInfo":{"totalResults":296,"resultsPerPage":5},"items":[{"kind":"youtube#searchResult","etag":"\"tbWC5XrSXxe1WOAx6MK9z4hHSU8/kvgjXpyJJ1CVnWs7i6kI_3-X0go\"","id":{"kind":"youtube#video","videoId":"drsH-pNpxho"},"snippet":{"publishedAt":"2015-04-23T14:21:19.000Z","channelId":"UCv7IjJclSgpfGUHnG171ovw","title":"A4 Pain - Painkiller #7 by Fez","description":"Insane new episode from A4 Pain Player: A4 Pain https://www.youtube.com/channel/UCVSS_0NReZbN3phT1OSKseQ Editor: Fez TOS ...","thumbnails":{"default":{"url":"https://i.ytimg.com/vi/drsH-pNpxho/default.jpg"},"medium":{"url":"https://i.ytimg.com/vi/drsH-pNpxho/mqdefault.jpg"},"high":{"url":"https://i.ytimg.com/vi/drsH-pNpxho/hqdefault.jpg"}},"channelTitle":"TheApokalypse4","liveBroadcastContent":"none"}},{"kind":"youtube#searchResult","etag":"\"tbWC5XrSXxe1WOAx6MK9z4hHSU8/t-udHC0CmSmK9Ej_q8KQgfHpyAo\"","id":{"kind":"youtube#video","videoId":"4kq8pW3ML0M"},"snippet":{"publishedAt":"2015-04-09T20:09:46.000Z","channelId":"UCv7IjJclSgpfGUHnG171ovw","title":"Apokalypse4 Killcams of the week - Episode 12","description":"Yes this is a weekly, episode we're trying to bring out more content for you guys, this is a example. Hope you enjoy! [CLICK SHOW MORE] This weeks winners!","thumbnails":{"default":{"url":"https://i.ytimg.com/vi/4kq8pW3ML0M/default.jpg"},"medium":{"url":"https://i.ytimg.com/vi/4kq8pW3ML0M/mqdefault.jpg"},"high":{"url":"https://i.ytimg.com/vi/4kq8pW3ML0M/hqdefault.jpg"}},"channelTitle":"TheApokalypse4","liveBroadcastContent":"none"}},{"kind":"youtube#searchResult","etag":"\"tbWC5XrSXxe1WOAx6MK9z4hHSU8/2_P60vNc53lyEX63yeKf_wlXYSk\"","id":{"kind":"youtube#video","videoId":"faizfXUbCAc"},"snippet":{"publishedAt":"2015-04-05T15:35:47.000Z","channelId":"UCv7IjJclSgpfGUHnG171ovw","title":"Apokalypse4 Challenges you - Episode 13","description":"Winner's chosen on the 1st of May, submit your ONLINE responses through twitter to @tehapokalypse4 and follow us for further information, good luck guys!","thumbnails":{"default":{"url":"https://i.ytimg.com/vi/faizfXUbCAc/default.jpg"},"medium":{"url":"https://i.ytimg.com/vi/faizfXUbCAc/mqdefault.jpg"},"high":{"url":"https://i.ytimg.com/vi/faizfXUbCAc/hqdefault.jpg"}},"channelTitle":"TheApokalypse4","liveBroadcastContent":"none"}},{"kind":"youtube#searchResult","etag":"\"tbWC5XrSXxe1WOAx6MK9z4hHSU8/JVw8gcWNDBq6A0k3NzNYydX7n4A\"","id":{"kind":"youtube#video","videoId":"vHTMfV7sJVg"},"snippet":{"publishedAt":"2015-03-25T16:10:24.000Z","channelId":"UCv7IjJclSgpfGUHnG171ovw","title":"A4 Sponge: Cleaning up - Episode 1","description":"Insane feeder and editor collaborate and produce a insane episode, enjoy guys! Subscribe :) http://bit.ly/SubToA4 10000 Teamtage ...","thumbnails":{"default":{"url":"https://i.ytimg.com/vi/vHTMfV7sJVg/default.jpg"},"medium":{"url":"https://i.ytimg.com/vi/vHTMfV7sJVg/mqdefault.jpg"},"high":{"url":"https://i.ytimg.com/vi/vHTMfV7sJVg/hqdefault.jpg"}},"channelTitle":"TheApokalypse4","liveBroadcastContent":"none"}},{"kind":"youtube#searchResult","etag":"\"tbWC5XrSXxe1WOAx6MK9z4hHSU8/imFn4cchjV1Gbp9F2zt9P-FgIvU\"","id":{"kind":"youtube#video","videoId":"AAMk41lxuyA"},"snippet":{"publishedAt":"2015-03-09T19:47:21.000Z","channelId":"UCv7IjJclSgpfGUHnG171ovw","title":"TheFantastic4 - ft. Gibby, Frizzy, Metal, Pregs by Cayzuh","description":"the ex a4 players return one last time. gibby https://www.youtube.com/user/ByGibbio frizzy https://www.youtube.com/user/OnyxFreeZy metal ...","thumbnails":{"default":{"url":"https://i.ytimg.com/vi/AAMk41lxuyA/default.jpg"},"medium":{"url":"https://i.ytimg.com/vi/AAMk41lxuyA/mqdefault.jpg"},"high":{"url":"https://i.ytimg.com/vi/AAMk41lxuyA/hqdefault.jpg"}},"channelTitle":"TheApokalypse4","liveBroadcastContent":"none"}}]}

Get youtube video Detail
To get the youtube video detail, you must have an valid youtube video.

https://www.googleapis.com/youtube/v3/videos?id=a2RA0vsZXf8&part=snippet,statistics&key=AIzaSyBqXp0Uo2ktJcMRpL_ZwF5inLTWZfsCYqY

Response Format:

{"kind":"youtube#videoListResponse","etag":"\"tbWC5XrSXxe1WOAx6MK9z4hHSU8/5O69VO4RLDboG2ONvOiRwnoX77I\"","pageInfo":{"totalResults":1,"resultsPerPage":1},"items":[{"kind":"youtube#video","etag":"\"tbWC5XrSXxe1WOAx6MK9z4hHSU8/7xlJyY3lj1NCugehSg-sBnEM0YQ\"","id":"a2RA0vsZXf8","snippet":{"publishedAt":"2010-11-21T04:52:18.000Z","channelId":"UCplkk3J5wrEl0TNrthHjq4Q","title":"\"Just A Dream\" by Nelly - Sam Tsui & Christina Grimmie","description":"Check out our epic song with Coke Bottles! https://www.youtube.com/watch?v=ZzuRvzsNpTU\n\nHope you guys like this duet between Christina Grimmie and Sam Tsui on \"Just A Dream\" originally by Nelly!\n\nAnd if you don't know Christina, definitely check out her stuff and subscribe to her, because she rocks!!\nhttp://www.youtube.com/zeldaxlove64\n\nShare this on Facebook!  http://on.fb.me/JustADreamSamChristina\n\nWe just opened an online store with shirts, cd's and other cool stuff here:\nhttp://www.kurthugoschneider.com/store\n\n\n--------------\n\nLinks\n\nKURT SCHNEIDER\nFacebook- http://www.facebook.com/KurtHugoSchneider\nTwitter- http://www.twitter.com/KurtHSchneider\n\nSAM TSUI\nFacebook- http://www.facebook.com/SamTsuiMusic\nTwitter- http://www.twitter.com/SamuelTsui\n\n---------------\n\n'Just A Dream' (originally Performed By Nelly)\nWritten By: Cornell Haynes, Frank Romano, Jim Jonsin, James Scheffer, Richard Butler\nPublished By: Universal Music Publishing / EMI Music Publishing / Reach Global Inc.","thumbnails":{"default":{"url":"https://i.ytimg.com/vi/a2RA0vsZXf8/default.jpg","width":120,"height":90},"medium":{"url":"https://i.ytimg.com/vi/a2RA0vsZXf8/mqdefault.jpg","width":320,"height":180},"high":{"url":"https://i.ytimg.com/vi/a2RA0vsZXf8/hqdefault.jpg","width":480,"height":360},"standard":{"url":"https://i.ytimg.com/vi/a2RA0vsZXf8/sddefault.jpg","width":640,"height":480},"maxres":{"url":"https://i.ytimg.com/vi/a2RA0vsZXf8/maxresdefault.jpg","width":1280,"height":720}},"channelTitle":"Kurt Hugo Schneider","categoryId":"10","liveBroadcastContent":"none","localized":{"title":"\"Just A Dream\" by Nelly - Sam Tsui & Christina Grimmie","description":"Check out our epic song with Coke Bottles! https://www.youtube.com/watch?v=ZzuRvzsNpTU\n\nHope you guys like this duet between Christina Grimmie and Sam Tsui on \"Just A Dream\" originally by Nelly!\n\nAnd if you don't know Christina, definitely check out her stuff and subscribe to her, because she rocks!!\nhttp://www.youtube.com/zeldaxlove64\n\nShare this on Facebook!  http://on.fb.me/JustADreamSamChristina\n\nWe just opened an online store with shirts, cd's and other cool stuff here:\nhttp://www.kurthugoschneider.com/store\n\n\n--------------\n\nLinks\n\nKURT SCHNEIDER\nFacebook- http://www.facebook.com/KurtHugoSchneider\nTwitter- http://www.twitter.com/KurtHSchneider\n\nSAM TSUI\nFacebook- http://www.facebook.com/SamTsuiMusic\nTwitter- http://www.twitter.com/SamuelTsui\n\n---------------\n\n'Just A Dream' (originally Performed By Nelly)\nWritten By: Cornell Haynes, Frank Romano, Jim Jonsin, James Scheffer, Richard Butler\nPublished By: Universal Music Publishing / EMI Music Publishing / Reach Global Inc."}},"statistics":{"viewCount":"96352554","likeCount":"804825","dislikeCount":"8957","favoriteCount":"0","commentCount":"132350"}}]}