Functions
trim() Function
The trim() function removes whitespaces and other predefined characters from both sides of a string.
Syntax
trim(string,charlist) ;
<?php
$string = " منتدى بي اتش بي ";
echo trim($string);// يتم طباعة منتدى بي اتش بي بدون فراغات قبلها وبعدها
$string2 = "montadaphp";
echo trim($string2, "map");// يتم طباعة ontdh
?> _________________________
is_dir() function
The is_dir() function checks whether the specified file is a directory.
This function returns TRUE if the directory exists.
Syntax
is_dir(file)
Example
<?php
$file = "images";
if(is_dir($file))
{
echo ("$file is a directory");
}
else
{
echo ("$file is not a directory");
}
?>
$file = "images";
if(is_dir($file))
{
echo ("$file is a directory");
}
else
{
echo ("$file is not a directory");
}
?>
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header() Function
The header() function sends a raw HTTP header to a client.It is important to notice that header() must be called before any actual output is sent (In PHP 4 and later, you can use output buffering to solve this problem):
<html>
<?php
// This results in an error.
// The output above is before the header() call
header('Location: http://www.example.com/');
?>
Syntax
header(string,replace,http_response_code)| Parameter | Description |
|---|---|
| string | Required. Specifies the header string to send |
| replace | Optional. Indicates whether the header should replace previous or add a second header. Default is TRUE (will replace). FALSE (allows multiple headers of the same type) |
| http_response_code | Optional. Forces the HTTP response code to the specified value (available in PHP 4.3 and higher) |
Tips and Notes
Note: Since PHP 4.4 this function prevents more than one header to be sent at once. This is a protection against header injection attacks.Example 1
Prevent page caching:| <?php // Date in the past header("Expires: Mon, 26 Jul 1997 05:00:00 GMT"); header("Cache-Control: no-cache"); header("Pragma: no-cache"); ?> <html> <body> ... ... |
Example 2
Let the user be prompted to save a generated PDF file (Content-Disposition header is used to supply a recommended filename and force the browser to display the save dialog box):| <?php header("Content-type:application/pdf"); // It will be called downloaded.pdf header("Content-Disposition:attachment;filename='downloaded.pdf'"); // The PDF source is in original.pdf readfile("original.pdf"); ?> <html> <body> ... ... |
_________________________
strtoupper() Function
Definition and Usage
The strtoupper() function converts a string to uppercase.Syntax
| strtoupper(string) |
Example
| <?php echo strtoupper("Hello WORLD!"); ?> |
HELLO WORLD!
_________________________
PHP end() Function
Definition and Usage
The end() function moves the internal pointer to, and outputs, the last element in the array.This function returns the value of the last element in the array on success.
Syntax
| end(array) |
| Parameter | Description |
|---|---|
| array | Required. Specifies the array to use |
Example
| <?php $people = array("Peter", "Joe", "Glenn", "Cleveland"); echo current($people) . "<br />"; echo end($people); ?> |
| Peter Cleveland |
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mysql_insert_id()
The mysql_insert_id() function returns the AUTO_INCREMENT ID generated from the previous INSERT operation.This function returns 0 if the previous operation does not generate an AUTO_INCREMENT ID, or FALSE on MySQL connection failure.
Syntax
| mysql_insert_id(connection) |
| Parameter | Description |
|---|---|
| connection | Optional. Specifies the MySQL connection. If not specified, the last connection opened by mysql_connect() or mysql_pconnect() is used. |
Tips and Notes
Note: Be sure to call mysql_insert_id() immediately after a query to get the correct value.Example
| <?php $con = mysql_connect("localhost", "peter", "abc123"); if (!$con) { die('Could not connect: ' . mysql_error()); } $db_selected = mysql_select_db("test_db",$con); $sql = "INSERT INTO person VALUES ('Børge','Refsnes','Sandnes','17')"; $result = mysql_query($sql,$con); echo "ID of last inserted record is: " . mysql_insert_id(); mysql_close($con); ?> |
ID of last inserted record is: 5
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Date() Function
The PHP date() function is used to format a time and/or date.
The PHP Date() Function
The PHP date() function formats a timestamp to a more readable date and time.
A timestamp is a sequence of characters, denoting the date and/or time at which a certain event occurred. 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 |
PHP Date() - Format the Date
The required format parameter in the date() function specifies how to format the date/time.Here are some characters that can be used:
- d - Represents the day of the month (01 to 31)
- m - Represents a month (01 to 12)
- Y - Represents a 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") . "<br />"; echo date("Y.m.d") . "<br />"; echo date("Y-m-d"); ?> |
| 2009/05/11 2009.05.11 2009-05-11 |
PHP Date() - Adding a Timestamp
The optional timestamp parameter in the date() function specifies a timestamp. If you do not specify a timestamp, the current date and time will be used.The mktime() function returns the Unix timestamp for a date.
The Unix timestamp contains the number of seconds between the Unix Epoch (January 1 1970 00:00:00 GMT) and the time specified.
Syntax for mktime()
| mktime(hour,minute,second,month,day,year,is_dst) |
| <?php $tomorrow = mktime(0,0,0,date("m"),date("d")+1,date("Y")); echo "Tomorrow is ".date("Y/m/d", $tomorrow); ?> |
Tomorrow is 2009/05/12
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