The HTML tag represents a container for external application or interactive content.
example :
<embed src="/html/yourfile.mdi" width="250" height="100" />
height, src, type, width
- The
<li>tag defines a list item. - The
<li>tag is used in ordered lists(<ol>), unordered lists (<ul>), and in menu lists (<menu>).
Example:
<ol>
<li>Coffee</li>
<li>Tea</li>
<li>Milk</li>
</ol>
<ul>
<li>Coffee</li>
<li>Tea</li>
<li>Milk</li>
</ul>used to embedded audio or video content
<audio controls>
<source src="horse.ogg" type="audio/ogg">
<source src="horse.mp3" type="audio/mpeg">
Your browser does not support the audio tag.
</audio>MP3, Ogg, Waw
autoplay, controls, loop, muted, preload, src
The <font> tag specifies the font face, font size, and color of text.
Example:
<font size="3" color="red">This is some text!</font>
<font size="2" color="blue">This is some text!</font>
<font face="verdana" color="green">This is some text!</font>size, color, face
The tag defines a row in an HTML table. Example:
<table>
<tr>
<th>Month</th>
<th>Savings</th>
</tr>
<tr>
<td>January</td>
<td>$100</td>
</tr>
</table>The HTML
tag specifies a section that contains only navigation links. Example:<nav>
<a href="/html/">HTML</a> |
<a href="/css/">CSS</a> |
<a href="/js/">JavaScript</a> |
<a href="/jquery/">jQuery</a>
</nav>- Audio and video were not part of previous HTML version specifications, however, both are the integral part of HTML5 specifications.
- Vector graphics is also an integral part of HTML5 such as SVG and canvas while vector graphics is possible in HTML with the help of various technologies such as VML, Silver-light, Flash, etc.
- In HTML, browser cache can be used as temporary storage. In case of HTML5, application cache, web SQL database, and web storage is used.
- HTML doesn’t allows JavaScript to run in web browser, it runs in same thread as browser interface. HTML5 allows JavaScript to run in background that is possible because of JS Web worker API in HTML5.
- HTML works smoothly with all old browsers while most of the modern web browsers have started supporting HTML5 specifications. These browsers include: Firefox, Mozilla, Chrome, Opera, Safari, etc.
Inline styles are the styles written under style attribute of any tag
- New selectors. With CSS3 you can select attributes with some fancy symbols (mostly modeled after regex, I believe). There are also new pseudo -classes that allow you to select child/sibling elements (eg :nth-child(even) allows you to select only the even numbered elements, extremely useful for alternating row colors in a table)
- Text Effects. Text-shadows and a handy new word-wrapping feature
- Transforms & Animations. Exactly like it sounds. You can specify timer properties and keyframes to create animations entirely using CSS
- Media Queries - enhancement of @media rules and "media" HTML markup element.
- Backgrounds and borders - describes background colors and images and the style of borders.
- Transitions - defines a property to animate the transitions between pseudo-classes.
- print only takes one parameter, while echo can have multiple parameters.
- print returns a value (1), so can be used as an expression.
- echo is slightly faster.
Syntax for both
The settype() function is used to set the type of a variable. parameters var_name, var_type
<?php
$var1='98';
$var2='01';
settype($var1, "integer");
settype($var2, "integer");
echo ($var1.'<br>');
echo ($var2.'<br>');
echo ($var1+$var2.'<br>');
?>The define() function defines a constant.
Constants are much like variables, except for the following differences:
- A constant's value cannot be changed after it is set
- Constant names do not need a leading dollar sign ($)
- Constants can be accessed regardless of scope
- Constant values can only be strings and numbers
<?php
define("GREETING","Hello you! How are you today?");
echo constant("GREETING");
const PI = 3.14;
$area = PI * 12;
?><?php
$favcolor = "red";
switch ($favcolor) {
case "red":
echo "Your favorite color is red!";
break;
case "blue":
echo "Your favorite color is blue!";
break;
case "green":
echo "Your favorite color is green!";
break;
default:
echo "Your favorite color is neither red, blue, nor green!";
}
?>$value = ($condition) ? 'Truthy Value' : 'Falsey Value';
<?php
function add_some_extra(&$string)
{
$string .= 'and something extra.';
}
$str = 'This is a string, ';
add_some_extra($str);
echo $str; // outputs 'This is a string, and something extra.'
?>ltrim, rtrim, strlen, strtolower, strtoupper, echo, print, trim
Format a local time/date date ( string $format [, int $timestamp = time() ] )
formats:
- d - day of Month
- D - textual representation of date
- M - short text month
- m - month in number
- Y - 4 digit representation of year
- y - 2 digit representation of year
- H - 24 hour format
- h - 12 hour format
- i - minutes with leading zeros
- s - seconds
attributes:
- autofocus
- cols
- rows
- maxlength
- form
- placeholder
Radio buttons let a user select ONE of a limited number of choices:
<form>
<input type="radio" name="gender" value="male" checked> Male<br>
<input type="radio" name="gender" value="female"> Female<br>
<input type="radio" name="gender" value="other"> Other
</form>checkbox allows the user to select multiple choices from given list
<form>
<input type="checkbox" name="gender" value="male" checked> Male<br>
<input type="checkbox" name="gender" value="female"> Female<br>
<input type="checkbox" name="gender" value="other"> Other
</form>used to set cookie
A cookie is often used to identify a user. A cookie is a small file that the server embeds on the user's computer. Each time the same computer requests a page with a browser, it will send the cookie too. With PHP, you can both create and retrieve cookie values.
setcookie($cookie_name, $cookie_value, time() + (86400 * 30), "/"); // 86400 = 1 day
$_COOKIE['cookie_name']used to open connection with mysql database
<?php
// we connect to example.com and port 3307
$link = mysql_connect('example.com:3307', 'mysql_user', 'mysql_password');
if (!$link) {
die('Could not connect: ' . mysql_error());
}
echo 'Connected successfully';
mysql_close($link);
// we connect to localhost at port 3307
$link = mysql_connect('127.0.0.1:3307', 'mysql_user', 'mysql_password');
if (!$link) {
die('Could not connect: ' . mysql_error());
}
echo 'Connected successfully';
mysql_close($link);
?>selecting database: $db = mysql_select_db(DB_NAME, $link) or die("Couldn't select database.");
This command is used to execute query against mysql database.
<?php
$result = mysql_query('SELECT * WHERE 1=1');
if (!$result) {
die('Invalid query: ' . mysql_error());
}
?>The mysql_num_rows() is used to get the number of rows in a MySQL result handle.
<?php
$con = mysql_connect("localhost", "root", "mypass");
$selectdb = mysql_select_db("tutorials",$con);
$result = mysql_query("select * from tutorials");
$number_of_rows = mysql_num_rows($result);
echo "Number of rows fetched are : ". $number_of_rows;
?>| Data Type Syntax | Maximum Size | Explanation |
|---|---|---|
| CHAR(size) | Maximum size of 255 characters. | Where size is the number of characters to store. Fixed-length strings. Space padded on right to equal size characters. |
| VARCHAR(size) | Maximum size of 255 characters. | Where size is the number of characters to store. Variable-length string. |
| TINYTEXT(size) | Maximum size of 255 characters. | Where size is the number of characters to store. |
| TEXT(size) | Maximum size of 65,535 characters. | Where size is the number of characters to store. |
| MEDIUMTEXT(size) | Maximum size of 16,777,215 characters. | Where size is the number of characters to store. |
| LONGTEXT(size) | Maximum size of 4GB or 4,294,967,295 characters. | Where size is the number of characters to store. |
| BINARY(size) | Maximum size of 255 characters. | Where size is the number of binary characters to store. Fixed-length strings. Space padded on right to equal size characters. (Introduced in MySQL 4.1.2) |
| VARBINARY(size) | Maximum size of 255 characters. | Where size is the number of characters to store. Variable-length string. (Introduced in MySQL 4.1.2) |
- CSS stands for Cascading Style Sheets
- CSS describes how HTML elements are to be displayed on screen, paper, or in other media
- CSS saves a lot of work. It can control the layout of multiple web pages all at once
- External stylesheets are stored in CSS files
Css are of three types:
- inline
- extrenal
- internal
An HTML marquee is a scrolling piece of text displayed either horizontally across or vertically down your webpage depending on the settings. This is created by using HTML tag.
<marquee attribute_name="attribute_value"....more attributes>
One or more lines or text message or image
</marquee>| Attribute | Description |
|---|---|
| width | This specifies the width of the marquee. This can be a value like 10 or 20% etc. |
| height | This specifies the height of the marquee. This can be a value like 10 or 20% etc. |
| direction | This specifies the direction in which marquee should scroll. This can be a value like up, down, left or right. |
| behavior | This specifies the type of scrolling of the marquee. This can have a value like scroll, slide and alternate. |
| scrolldelay | This specifies how long to delay between each jump. This will have a value like 10 etc. |
| scrollamount | This specifies the speed of marquee text. This can have a value like 10 etc. |
| loop | This specifies how many times to loop. The default value is INFINITE, which means that the marquee loops endlessly. |
| bgcolor | This specifies background color in terms of color name or color hex value. |
| hspace | This specifies horizontal space around the marquee. This can be a value like 10 or 20% etc. |
| vspace | This specifies vertical space around the marquee. This can be a value like 10 or 20% etc. |
Php is loosely-typed language because in php you can use a variable without declaring it. If a variable is used to store integer then you can still access that integer as string and reverse is possible too. Php manages that automatically.
This kind of things are not possible in strictly type languages like c#. For example, in c# you can’t use variable without declaring it and can’t use string variable to integer without casting it.
An important thing to note is that, being loosely-typed language it leads developer to write bad code. Which can cause some issues (I had one data type issue ). Though it is vary useful for writing highly dynamic applications.
Find the position of the first occurrence of "php" inside the string:
<?php
echo strpos("I love php, I love php too!","php");
?>The fmod() function returns the remainder (modulo) of x/y.
<?php
$x = 7;
$y = 2;
$result = fmod($x,$y);
echo $result;
// $result equals 1, because 2 * 3 + 1 = 7
?>Appends form-data into the URL in name/value pairs The length of a URL is limited (about 3000 characters) Never use GET to send sensitive data! (will be visible in the URL) Useful for form submissions where a user want to bookmark the result GET is better for non-secure data, like query strings in Google
Appends form-data inside the body of the HTTP request (data is not shown is in URL) Has no size limitations Form submissions with POST cannot be bookmarked
The method attribute specifies how to send form-data (the form-data is sent to the page specified in the action attribute). The form-data can be sent as URL variables (with method="get") or as HTTP post transaction (with method="post").
The action attribute specifies where to send the form-data when a form is submitted.
The enctype attribute specifies how the form-data should be encoded when submitting it to the server.
<?php
$dbhost = 'localhost:3036';
$dbuser = 'root';
$dbpass = 'rootpassword';
$conn = mysql_connect($dbhost, $dbuser, $dbpass);
if(! $conn ) {
die('Could not connect: ' . mysql_error());
}
echo 'Connected successfully';
$sql = 'CREATE Database test_db';
$retval = mysql_query( $sql, $conn );
if(! $retval ) {
die('Could not create database: ' . mysql_error());
}
echo "Database test_db created successfully\n";
mysql_close($conn);
?>The statements inside your source files are generally executed from top to bottom, in the order that they appear. Control flow statements, however, break up the flow of execution by employing decision making, looping, and branching, enabling your program to conditionally execute particular blocks of code.
What is a PHP Session? When you work with an application, you open it, do some changes, and then you close it. This is much like a Session. The computer knows who you are. It knows when you start the application and when you end. But on the internet there is one problem: the web server does not know who you are or what you do, because the HTTP address doesn't maintain state.
Session variables solve this problem by storing user information to be used across multiple pages (e.g. username, favorite color, etc). By default, session variables last until the user closes the browser.
So; Session variables hold information about one single user, and are available to all pages in one application.
<?php
// Start the session
session_start();
?>
<!DOCTYPE html>
<html>
<body>
<?php
// Set session variables
$_SESSION["favcolor"] = "green";
$_SESSION["favanimal"] = "cat";
echo "Session variables are set.";
?>
</body>
</html>The global keyword is used to access a global variable from within a function. To do this, use the global keyword before the variables (inside the function):
<?php
$x = 5;
$y = 10;
function myTest() {
global $x, $y;
$y = $x + $y;
}
myTest();
echo $y; // outputs 15
?>Rules for PHP variables:
- A variable starts with the $ sign, followed by the name of the variable
- A variable name must start with a letter or the underscore character
- A variable name cannot start with a number
- A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )
- Variable names are case-sensitive ($age and $AGE are two different variables)
With loop control statements, you can repeatedly execute a block of code. There are two types of loops: for statements loop a specific number of times, and keep track of each iteration with an incrementing index variable.