Encoding

Posted on September 26, 2012 by admin

Here is a generated php link:

<a href="secondpage.php?name=Kevin&id=1">Secondpage</a>

1	<a href="secondpage.php?name=Kevin&id=1">Secondpage</a>

What If for example the value of “name”, instead of “Kevin”, contains sensible characters like “&” or spaces that interfere with an URL?

<a href="secondpage.php?name=Kevin&&id=1">Secondpage</a>

1	<a href="secondpage.php?name=Kevin&&id=1">Secondpage</a>

We are going to use URL encoding

We are going to do some transformations using php to make sure the value is safe before it is sent to the URL

Lets start by setting up some variables:

<?php
	$url_page = 'php/created/page/url.php';
	$param1 = 'this is a string';
	$param2 = '"bad"/<>characters$';
	$linktext = "<Click> & you'll see";
?>

<?php

$url_page = 'php/created/page/url.php';

$param1 = 'this is a string';

$param2 = '"bad"/<>characters$';

$linktext = "<Click> & you'll see";

How can we put together a URL that’s going to be encoded and not break for us?

We are going to use the following functions:

rawurlencode() – we will use this before the question mark;
urlencode() – we will use this after the question mark;
htmlspecialchars() – escapes any html that might due bad things to our html page.

<?php
    // this gives us a clean url to use
	$url = "http://www.mysite.com/";
	$url .= rawurlencode($url_page); // we use rawurlencode because this is before the question mark
	$url .= "?param1=".urlencode($param1); // we use urlencode because it's after the question mark
	$url .= "&param2=".urlencode($param2);
?>

<?php

// this gives us a clean url to use

$url = "http://www.mysite.com/";

$url .= rawurlencode($url_page); // we use rawurlencode because this is before the question mark

$url .= "?param1=".urlencode($param1); // we use urlencode because it's after the question mark

$url .= "&param2=".urlencode($param2);

Our URL will be like this:

<a href="<? echo htmlspecialchars($url); ?>"><? echo htmlspecialchars($linktext); ?></a>

1	<a href="<? echo htmlspecialchars($url); ?>"><? echo htmlspecialchars($linktext); ?></a>

We’ve done two things, cleaned up the link so that we can use it and then we’ve done our htmlspecialchars so that we can safely display that link.

URL Values

Posted on September 26, 2012 by admin

To pass values we add “?” to a page like this:

<a href="secondpage.php?id=1&name=john">Secondpage</a>

1	<a href="secondpage.php?id=1&name=john">Secondpage</a>

<?php
$_GET;
$id = $_GET['id'];
$name = $_GET['name'];
?>

<?php

$_GET;

$id = $_GET['id'];

$name = $_GET['name'];

$_GET is an associative array of variables passed to the current script via the URL parameters.

We can pass these variables into an associative array which we can access using $_GET.

Array Functions

Posted on September 21, 2012 by admin

We begin by defining an array:

$array1 = array(1, 3, 5, 19, 90, 45, 23);

1	$array1 = array(1, 3, 5, 19, 90, 45, 23);

Now lets analyze the following array functions

1. Count Function

Counts all elements in an array

 count($array1);  // returns 7

1	count($array1); // returns 7

2. Max Function

Finds the highest value in an array

 max($array1); // returns 90

1	max($array1); // returns 90

3. Min Function

Finds the lowest value in an array

 min($array1); // returns 1

1	min($array1); // returns 1

4. Sort and Rsort Function

Sort – sorts an array; Rsort – sorst the array in reverse order.

sort($array1); print_r($array1); // returns array(1, 3, 5, 19, 23, 45, 90);
   
rsort($array1); print_r($array1); // returns array(90, 45, 23, 19, 5, 3, 1);

sort($array1); print_r($array1); // returns array(1, 3, 5, 19, 23, 45, 90);

rsort($array1); print_r($array1); // returns array(90, 45, 23, 19, 5, 3, 1);

5. Implode Function

This function joins array elements with a string

$string1 = implode(" * ", $array1);  // returns 1 * 3 * 5 * 19 * 23 * 45 * 90

1	$string1 = implode(" * ", $array1); // returns 1 * 3 * 5 * 19 * 23 * 45 * 90

This is very helpful for array’s that contain names. We can display them and separate each name by comma.

$names = array("Mike", "John", "Elmo");
   
$names_string = implode(", ", $names);

echo $names_string; //returns Mike, John, Elmo

$names = array("Mike", "John", "Elmo");

$names_string = implode(", ", $names);

echo $names_string; //returns Mike, John, Elmo

6. Explode Function

Returns an array of strings splitting it on boundaries formed by the string delimiter.

$new_array = explode(" * ", $string1); // returns array(1, 3, 5, 19, 23, 45, 90)

1	$new_array = explode(" * ", $string1); // returns array(1, 3, 5, 19, 23, 45, 90)

To see the results we can print it

print_r($new_array);

1	print_r($new_array);

7. in_array Function

Checks if a value exists in an array, returns true of false.

in_array(3, $array1); // In this case it returns true, 3 being an element inside $array1

1	in_array(3, $array1); // In this case it returns true, 3 being an element inside $array1

Arrays

Posted on September 20, 2012 by admin

$array1 = array(4, 8, 15, 16, 32);

echo $array[1];

echo $array[0];

$array1 = array(4, 8, 15, 16, 32);

echo $array[1];

echo $array[0];

This returns position 1, meaning value “8″ while the second echo returns position 0, meaning the value “4″.

Important: arrays are numbered starting with 0.

$array2 = array(6, "fox", "dog", array("x", "y", "z"));

echo $array2[2];

$array2 = array(6, "fox", "dog", array("x", "y", "z"));

echo $array2[2];

This returns “dog”.

What if we do this?

echo $array2[3];

1	echo $array2[3];

This will return “Array”. We can put this inside another variable or we can echo a value from it like this:

echo $array2[3][1];

1	echo $array2[3][1];

This will return “y”

What happens if we want to put things into the pockets of the array?

$array2[3] = "cat";

1	$array2[3] = "cat";

This will replace “dog” with “cat”.

We can lable the array

$array3 = array("first_name" => "Kevin", "last_name" => "Scott");

echo $array3["first_name"];

$array3 = array("first_name" => "Kevin", "last_name" => "Scott");

echo $array3["first_name"];

This will echo “Kevin”.

$array3["first_name"] = "Josh";

1	$array3["first_name"] = "Josh";

This will replace Kevin with Josh

This will print the array’s content. Great for debugging

print_r($array2); // Print Readable

1	print_r($array2); // Print Readable

For a better wiew of the content of the array we can use the “pre” tag, which is a HTML command that says “don’t apply any formatting”.

Php Blog

Un Blog despre PHP

Encoding

URL Values

Array Functions

Now lets analyze the following array functions

1. Count Function

2. Max Function

3. Min Function

4. Sort and Rsort Function

5. Implode Function

6. Explode Function

7. in_array Function

Arrays