Said Khorramshahgol's List: PHP Tutorial

PHP If...Else Statements 1

Dec 04, 08

www.w3schools.com/...php_if_else.asp

The following example will output "Have a nice weekend!" if the current day is Friday, and "Have a nice Sunday!" if the current day is Sunday. Otherwise it will output "Have a nice day!":

<html> <body>

<?php $d=date("D"); if ($d=="Fri")   echo "Have a nice weekend!";  elseif ($d=="Sun")   echo "Have a nice Sunday!";  else   echo "Have a nice day!";  ?>

</body> </html>

PHP String 4

Dec 04, 08

www.w3schools.com/...php_string.asp
- The concatenation operator (.) is used to put two string values together.
  
  To concatenate two variables together, use the dot (.) operator:
  
  <?php $txt1="Hello World"; $txt2="1234"; echo $txt1 . " " . $txt2; ?>
- The concatenation operator (.) is used to put two string values together.
  
  To concatenate two variables together, use the dot (.) operator:
  
  <?php $txt1="Hello World"; $txt2="1234"; echo $txt1 . " " . $txt2; ?>
  
  The output of the code above will be:
  
  Hello World 1234
- The strlen() function is used to find the length of a string.
  
  Let's find the length of our string "Hello world!":
  
  <?php echo strlen("Hello world!"); ?>
  
  The output of the code above will be:
  
  12
- The strpos() function is used to search for a string or character within a string.
  
  If a match is found in the string, this function will return the position of the first match. If no match is found, it will return FALSE.
  
  Let's see if we can find the string "world" in our string:
  
  <?php echo strpos("Hello world!","world"); ?>
  
  The output of the code above will be:
  
  6
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PHP Variables 3

Dec 04, 08

www.w3schools.com/...php_variables.asp
- All variables in PHP start with a $ sign symbol.
  
  The correct way of setting a variable in PHP:
  
  $var_name = value;
- Let's try creating a variable with a string, and a variable with a number:
  
  <?php $txt = "Hello World!"; $number = 16; ?>
- In PHP a variable does not need to be declared before being set.
  
  In the example above, you see that you do not have to tell PHP which data type the variable is.
  
  PHP automatically converts the variable to the correct data type, depending on how they are set.
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PHP Syntax 2

Dec 04, 08

www.w3schools.com/...php_syntax.asp
- Basic PHP Syntax
  
  A PHP scripting block always starts with <?php and ends with ?>. A PHP scripting block can be placed anywhere in the document.
- The file must have the .php extension. If the file has a .html extension, the PHP code will not be executed.
PHP Looping 3

Dec 04, 08

www.w3schools.com/...php_looping.asp
- In PHP we have the following looping statements:
  
  while - loops through a block of code if and as long as a specified condition is true
  
  do...while - loops through a block of code once, and then repeats the loop as long as a special condition is true
  
  for - loops through a block of code a specified number of times
  
  foreach - loops through a block of code for each element in an array
- Syntax
  
  for (init; cond; incr) { code to be executed; }
  
  Parameters:
  
  init: Is mostly used to set a counter, but can be any code to be executed once at the beginning of the loop statement.
  
  cond: Is evaluated at beginning of each loop iteration. If the condition evaluates to TRUE, the loop continues and the code executes. If it evaluates to FALSE, the execution of the loop ends.
  
  incr: Is mostly used to increment a counter, but can be any code to be executed at the end of each loop.
  
  Note: Each of the parameters can be empty or have multiple expressions separated by commas.
  
  cond: All expressions separated by a comma are evaluated but the result is taken from the last part. This parameter being empty means the loop should be run indefinitely. This is useful when using a conditional break statement inside the loop for ending the loop.
- The foreach Statement
  
  The foreach statement is used to loop through arrays.
  
  For every loop, the value of the current array element is assigned to $value (and the array pointer is moved by one) - so on the next loop, you'll be looking at the next element.
  
  Syntax
  
  foreach (array as value) { code to be executed; }
  
  Example
  
  The following example demonstrates a loop that will print the values of the given array:
  
  <html> <body>
  
  <?php $arr=array("one", "two", "three");
  
  foreach ($arr as $value) { echo "Value: " . $value . "<br />"; } ?>
  
  </body> </html>
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PHP Include File include() and require() 5

Dec 04, 08

www.w3schools.com/...php_includes.asp

Server Side Includes

You can insert the content of a file into a PHP file before the server executes it, with the include() or require() function. The two functions are identical in every way, except how they handle errors. The include() function generates a warning (but the script will continue execution) while the require() function generates a fatal error (and the script execution will stop after the error).

These two functions are used to create functions, headers, footers, or elements that can be reused on multiple pages.

Now, let's assume we have a standard menu file that should be used on all pages (include files usually have a ".php" extension). Look at the "menu.php" file below:

<html> <body>

<a href="http://www.w3schools.com/default.php">Home</a> | <a href="http://www.w3schools.com/about.php">About Us</a> |  <a href="http://www.w3schools.com/contact.php">Contact Us</a>

The three files, "default.php", "about.php", and "contact.php" should all include the "menu.php" file. Here is the code in "default.php":

<?php include("menu.php"); ?>

<h1>Welcome to my home page</h1>

<p>Some text</p>

</body> </html>

If you look at the source code of the "default.php" in a browser, it will look something like this:

<html> <body> <a href="default.php">Home</a> | <a href="about.php">About Us</a> |  <a href="contact.php">Contact Us</a> <h1>Welcome to my home page</h1> <p>Some text</p> </body> </html>

And, of course, we would have to do the same thing for "about.php" and "contact.php". By using include files, you simply have to update the text in the "menu.php" file if you decide to rename or change the order of the links or add another web page to the site.

If you include a file with the include() function and an error occurs, you might get an error message like the one below.

PHP code:

<html> <body>  <?php include("wrongFile.php"); echo "Hello World!"; ?>  </body> </html>

Error message:

Warning: include(wrongFile.php) [function.include]: failed to open stream: No such file or directory in C:\home\website\test.php on line 5

Warning: include() [function.include]: Failed opening 'wrongFile.php' for inclusion (include_path='.;C:\php5\pear') in C:\home\website\test.php on line 5

Hello World!

Notice that the echo statement is still executed! This is because a Warning does not stop the script execution.

Now, let's run the same example with the require() function.

PHP code:

<html> <body>  <?php require("wrongFile.php"); echo "Hello World!"; ?>  </body> </html>

Error message:

Warning: require(wrongFile.php) [function.require]: failed to open stream: No such file or directory in C:\home\website\test.php on line 5

Fatal error: require() [function.require]: Failed opening required 'wrongFile.php' (include_path='.;C:\php5\pear') in C:\home\website\test.php on line 5

The echo statement was not executed because the script execution stopped after the fatal error.

It is recommended to use the require() function instead of include(), because scripts should not continue executing if files are missing or misnamed.

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PHP Date() 8

Dec 04, 08

www.w3schools.com/...php_date.asp
- The PHP Date() Function
  
  The PHP date() function formats a timestamp to a more readable date and time.
- Syntax
  
  date(format,timestamp)
  
  Parameter Description
  format Required. Specifies the format of the timestamp
  timestamp Optional. Specifies a timestamp. Default is the current date and time (as a timestamp)
- PHP Date - What is a Timestamp?
  
  A timestamp is the number of seconds since January 1, 1970 at 00:00:00 GMT. This is also known as the Unix Timestamp.
- The first parameter in the date() function specifies how to format the date/time. It uses letters to represent date and time formats. Here are some of the letters that can be used:
  
  d - The day of the month (01-31)
  
  m - The current month, as a number (01-12)
  
  Y - The current year in four digits
- Other characters, like"/", ".", or "-" can also be inserted between the letters to add additional formatting:
  
  <?php echo date("Y/m/d"); echo "<br />"; echo date("Y.m.d"); echo "<br />"; echo date("Y-m-d"); ?>
  
  The output of the code above could be something like this:
  
  2006/07/11 2006.07.11 2006-07-11
- PHP Date - Adding a Timestamp
  
  The second parameter in the date() function specifies a timestamp. This parameter is optional. If you do not supply a timestamp, the current time will be used.
- The mktime() function returns the Unix timestamp for a specified date.
- Syntax
  
  mktime(hour,minute,second,month,day,year,is_dst)
  
  To go one day in the future we simply add one to the day argument of mktime():
  
  <?php $tomorrow = mktime(0,0,0,date("m"),date("d")+1,date("Y"));
  echo "Tomorrow is ".date("Y/m/d", $tomorrow); ?>
  
  The output of the code above could be something like this:
  
  Tomorrow is 2006/07/12
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PHP POST 4

Dec 04, 08

www.w3schools.com/...php_post.asp
- The $_POST variable is used to collect values from a form with method="post".
- Information sent from a form with the POST method is invisible to others and has no limits on the amount of information to send.
- Example
  
  <form action="welcome.php" method="post">
- The "welcome.php" file can now use the $_POST variable to catch the form data (notice that the names of the form fields will automatically be the ID keys in the $_POST array):
  
  Welcome <?php echo $_POST["name"]; ?>.<br /> You are <?php echo $_POST["age"]; ?> years old!
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PHP GET 6

Dec 04, 08

www.w3schools.com/php_get.asp
- The $_GET variable is used to collect values from a form with method="get".
- Information sent from a form with the GET method is visible to everyone (it will be displayed in the browser's address bar) and it has limits on the amount of information to send (max. 100 characters).
- Example
  
  <form action="welcome.php" method="get">
- The "welcome.php" file can now use the $_GET variable to catch the form data (notice that the names of the form fields will automatically be the ID keys in the $_GET array):
  
  Welcome <?php echo $_GET["name"]; ?>.<br /> You are <?php echo $_GET["age"]; ?> years old!
- Note: When using the $_GET variable all variable names and values are displayed in the URL. So this method should not be used when sending passwords or other sensitive information! However, because the variables are displayed in the URL, it is possible to bookmark the page. This can be useful in some cases.
- The $_REQUEST Variable
  
  The PHP $_REQUEST variable contains the contents of both $_GET, $_POST, and $_COOKIE.
  
  The PHP $_REQUEST variable can be used to get the result from form data sent with both the GET and POST methods.
  
  Example
  
  Welcome <?php echo $_REQUEST["name"]; ?>.<br /> You are <?php echo $_REQUEST["age"]; ?> years old!
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Parameter	Description
format	Required. Specifies the format of the timestamp
timestamp	Optional. Specifies a timestamp. Default is the current date and time (as a timestamp)

PHP File 6

Dec 04, 08

www.w3schools.com/...php_file.asp

Opening a File

The fopen() function is used to open files in PHP.

The first parameter of this function contains the name of the file to be opened and the second parameter specifies in which mode the file should be opened:
<html> <body>

<?php $file=fopen("welcome.txt","r"); ?>

</body> </html>
Note: If the fopen() function is unable to open the specified file, it returns 0 (false).

Closing a File

The fclose() function is used to close an open file:

<?php $file = fopen("test.txt","r");

//some code to be executed

fclose($file); ?>

The feof() function checks if the "end-of-file" (EOF) has been reached.

The feof() function is useful for looping through data of unknown length.

Reading a File Line by Line

The fgets() function is used to read a single line from a file.

Note: After a call to this function the file pointer has moved to the next line.

Example

The example below reads a file line by line, until the end of file is reached:

<?php $file = fopen("welcome.txt", "r") or exit("Unable to open file!"); //Output a line of the file until the end is reached while(!feof($file))   {   echo fgets($file). "<br />";   } fclose($file); ?>

Reading a File Character by Character

The fgetc() function is used to read a single character from a file.

Note: After a call to this function the file pointer moves to the next character.

Example

The example below reads a file character by character, until the end of file is reached:
<?php $file=fopen("welcome.txt","r") or exit("Unable to open file!"); while (!feof($file)) { echo fgetc($file); } fclose($file); ?>

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Said Khorramshahgol

10 items | 16 visits

Updated on Dec 05, 08
Created on Dec 04, 08

Category: Computers & Internet

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Said Khorramshahgol's List: PHP Tutorial

PHP If...Else Statements 1

PHP String 4

PHP Variables 3

PHP Syntax 2

Basic PHP Syntax

PHP Looping 3

Syntax

The foreach Statement

Syntax

Example

PHP Include File include() and require() 5

Server Side Includes

PHP Date() 8

The PHP Date() Function

Syntax

PHP Date - What is a Timestamp?

PHP Date - Adding a Timestamp

Syntax

PHP POST 4

Example

PHP GET 6

Example

The $_REQUEST Variable

Example

PHP File 6

Opening a File

Closing a File

Reading a File Line by Line

Example

Reading a File Character by Character

Example

List Info