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#8885 One Mod Rewrite Rule Won'T Work

Posted by HartleySan on 28 July 2012 - 10:59 AM

If "hiv" is never followed by an e, you could change the one regex as follows:
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#6644 Just Started This Book Today!

Posted by rob on 26 March 2012 - 10:53 AM

It does affect something it affects the source code layout, which is the whole point of using it, to make source code more readable.
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#3208 Some Tips When It Comes To Mysql Queries

Posted by Antonio Conte on 20 August 2011 - 11:19 PM

1. Always name your tables the same way:
There are best practice rules for naming tables. They should always be lowercase, split by underscore ( _ ) and named in plural. If you need to build tables for several purposes, (forums, shops, fruits) prefix them so the appear next to each other.


2. Use normalization rules(!!!) when creating a structure for tables
Larry explains the different forms of normalization very good in this book. Read it thoroughly, UNDERSTAND it, and plan your tables well. The rules are really not that hard to understand, and will allow you to cross-reference tables in an easy way later on. It will make you understand how the data you are using are working. It will make your systems a lot easier to build on and to introduce new features. I promise you, THIS is how you become a wizard when it comes to working with data in several tables.

3. Use white space(!) and use UPPERCASE for mysql functions (See tip #4!)
When your queries becomes increasingly more complex, you should really follow these tips. To demonstrate, I will give you two versions of the exact same code:

CREATE VIEW view_goals_per_game AS

SELECT league.season AS season,
league.id AS league_id,
league.name AS league_name,
goals.match_id AS match_id,
clubs1.name AS hometeam,
clubs2.name AS awayteam,
players.id AS player_id,
CONCAT( players.fornavn, ' ', players.etternavn ) AS player_name,
goals.goal_time AS goal_time,
games.kickoff_time AS kickoff_time

FROM abc_players_goals AS goals

INNER JOIN cnk_soccer_games AS games ON ( goals.match_id = games.id )
INNER JOIN cnk_soccer_clubs AS clubs1 ON ( games.club1_id = clubs1.id )
INNER JOIN cnk_soccer_clubs AS clubs2 ON ( games.club2_id = clubs2.id )
INNER JOIN abc_players AS players ON ( goals.player_id = players.id )
INNER JOIN cnk_soccer_league AS league ON ( league.id = games.league_id )

LIMIT 0, 1000

create view view_goals_per_game as select league.season as season, league.id as league_id, league.name as league_name, goals.match_id as match_id, clubs1.name as hometeam, clubs2.name as awayteam, players.id as player_id, concat( players.fornavn, ' ', players.etternavn ) as player_name, goals.goal_time, games.kickoff_time from abc_players_goals as goals inner join cnk_soccer_games as games on ( goals.match_id = games.id ) inner join cnk_soccer_clubs as clubs1 on ( games.club1_id = clubs1.id ) inner join cnk_soccer_clubs as clubs2 on ( games.club2_id = clubs2.id ) inner join abc_players as players on ( goals.player_id = players.id ) inner join cnk_soccer_league as league on ( league.id = games.league_id ) limit 0 , 1000

Whick one would you like to maintain? :blink:

4: Save your queries in a text editor

Yes! It sound idiotic, right? It's not. Think of this happening: You accidentally delete, modify or overwrite a query you've used a lot of time on. It will save you a lot of time, tears and the life of a few keyboards! This is also leading up tip number 5.

5. Use views instead of customizing your dataset in PHP(!)
This is a real life-saver. Think of it as including ONE central PHP file instead on chancing 10 documents every time you make a change. The views should be written to display AS MUCH information as possible. Try to think of every scenario you may want to use the data. Views are, with a few exceptions, for displaying data; hence it's name.

NOTE: After the creation of a view, you CANNOT modify it. This is why you should follow step 4.

- Views are really easy to create:
[u][i]CREATE VIEW the_name_of_the_view AS[/i][/u]
FROM table1

The query used in tip #3 is a view. It would allow you to sort by a specific league, match_id, player_id or by kickoff_time. The view is used to display statistic about the goal scorer in a football match. (soccer for americans) The table for saving goal statistic has three rows(!). Match_id, player_id and goal_time. This is good data normalization, and minimizes redundancy and make for consistent data. That means the table players_goals need to be linked with other tables that holds data about the specific match and the specific player. This is the reason for create a view.

Don't see the point of this?
There really is one - I promise! By writing a view that is general and display a lot of data, I can write SIMPLE queries to get different results:

1. Last five goal scorers with name of both teams, player name and goal time
SELECT hometeam, awayteam, player_name, goal_time
FROM view_goals_per_game 
ORDER BY kickoff_time DESC

2. Display players with most goals in descending order
SELECT player_name, COUNT(*) as goals
FROM view_goals_per_game
GROUP BY player_id

3. Display all goals by a specific player
 SELECT hometeam, awayteam, player_name, goal_time
FROM view_goals_per_game
WHERE player_id = 10
ORDER BY kickoff_time DESC

4. Find all goals in a specific match
SELECT hometeam, awayteam, player_name, goal_time
FROM view_goals_per_game
WHERE match_id = 837

Does it start to make some sense? Instead of repeating and modifying the same hard-to-grasp code over and over again (see tip #3), use a view to make your life simpler. :)

Hope this has helped someone. I have been thinking about writing a lot of different tips when it comes to MySQL. I've been thinking about writing a guide to joins for example. I really don't know if this interests someone or not.

Hoping others will also share tips and experiences when it comes to MySQL. :)
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#14402 Really Disturbing

Posted by margaux on 1 May 2013 - 4:56 PM

Hey xto, I'm going to try to say this in the nicest way possible -  You're in danger of trying people's patience not because you ask questions, we like questions, but because you ask questions in a way that doesn't provide the information needed to try to answer them.


1. please read the forum guidelines - Look for the little grey text bottom right of most pages, labelled Guidelines

2. please post only RELEVANT code and error messages within code tags. We don't need to see the entire output from your error message. It's actually distracting. Use code tags which are on the edit bar and they look like <>

3. post the relevant CODE, you keep posting the error message but not any code.

4. You should start a new thread for each new question. One reason for doing so is that other people with the same question can search and find your thread. If your question is part of another thread, it won't be found and won't help others.

5. You're asking questions that you should be able to solve 1 because the level of  experience for this book expects you know some basic debugging strategies and 2. with a little bit of online searching you would get some pointers as to where to look for the cause of your error.


I really shouldn't answer your question given the above but ...


somewhere in your code you are referencing an array value using 'sale_price' as the index, which doesn't exist. I'm going to hazard a guess that you have a line that includes $row['sale_price']. From the error dump you posted, you will see there is no index 'sale_price' but there is one named 'price'. Given what info you've provided that's all I can help with. If this doesn't help solve the problem, start a new thread and post the code that is causing the error :)

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#6039 Securing Video

Posted by Paul Swanson on 17 February 2012 - 5:40 PM

In addition to Rob's suggestion, you could use a .htaccess file in the directory housing the video to protect it from browsing. This will prevent any browser from accessing the directory (but PHP will still be able to access it):

# disable directory browsing
Options All -Indexes

# prevent folder listing
IndexIgnore *

# prevent access to any file
<FilesMatch "^.*$">
 Order Allow,Deny
 Deny from all

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#20304 Php/mysql Error Message?

Posted by Emilie on 20 August 2014 - 6:55 AM



Another typo:


The closing quotation mark is missing.


Also, if your ID is numeric, you should not quote it:

where (ID='23')


If this doesn't do the trick, I would suggest testing a few lines only at a time, until you find where the query goes wrong.


I hope this helps,



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#15289 Use Data Type Enum For Form Drop-Down Options

Posted by margaux on 2 July 2013 - 5:02 PM

Glad I could provide a little help. When I'm struggling with some code, I use var_dump and print_r to see what is being returned. Then I know how to manipulate the data.

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#13394 Pls Help Need Urgent Help. The .Inc Extension. Chapter 11

Posted by margaux on 11 March 2013 - 4:45 AM

It's difficult to debug when the code is presented in this way. Please would you use code tags.


At first look, no error immediately jumps out. Which line is line 46? Look at that line and the few lines before it.


Probably not causing this error but it looks like you may have a typo on the tablename in the SELECT statement - users instead of usera?

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#13112 Forms In Javascript Or Php?

Posted by HartleySan on 19 February 2013 - 10:38 AM

Awesomo, to give you a concrete example, I'm going to use Jonathon's example above because I think it's a good example.
First off, you'll want to attach a JS event handler to the form so that when the form is submitted, JS intercepts the form submission and allows you to do whatever you need to before the form is actually submitted.
This can be accomplished as follows:
document.forms[0].onsubmit = function () {
  return false;
On any HTML page that contains at least one form, JS provides you with the forms array, which is a property of the document object. forms[0] always applies to the first form on the page. You can adjust the array index as need be.
The return false statement actually stops the form from being submitted. (Don't worry though, as we'll actually force the form to be submitted in a second, assuming everything is okay.)
Next, let's imagine that we have a user name text input that must be only letters and numbers, as Jonathon said. Here's a simple JS regex we can write to test for that:
document.forms[0].onsubmit = function () {
  if (/^[A-Za-z0-9]+$/.test(this.elements[0].value)) {
  return false;
The above if statement tests that the user name text input contains only letters (either uppercase or lowercase) and numbers (and is not an empty string). I should note that I make several assumptions with this code:
The user name text input is the first input in the form. This can be seen by the this.elements[0] in the if statement. In this case, this refers to the form object we're interested in, and elements is an array attached to all JS form objects that allows you to access all the inputs items in the form. Naturally, elements[0] refers to the first element in the form. If you'd rather check the user name text input by ID (assuming the ID is "username"), you can replace this.elements[0] with document.getElementById('username'). The value property at the end will give you the actual string entered into the text input object.
If the above if statement evaluates to true, then we can assume that the user name does in fact only contain letters and numbers. That being the case, we should then submit the form normally.
However, if the if statement returns false, then we should change the border of the user name text input to red.
The following code will do just that:
document.forms[0].onsubmit = function () {
  if (/^[A-Za-z0-9]+$/.test(this.elements[0].value)) {
  } else {
    this.elements[0].style.border = '#F00 solid 2px';
  return false;
As before, this refers to the form object in question. this.submit() will actually submit the form as if JS never intercepted the form submit request in the first place.
If the if statement fails, then we use this.elements[0] (or document.getElementById('username'), if you want) to reference the user name text input object, and then change the border to a 2-pixel red border.
That's the basic concept to simple JS form validation built on top of standard PHP form validation.
One of the keys to this method is that you only submit the form when everything is okay.
And naturally, the concepts above can be rinsed and repeated as many times as necessary to validate all your form input.
I hope that helps.

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#11924 Very Basic: Headers Vs Cookies

Posted by HartleySan on 27 December 2012 - 8:38 PM

The order doesn't matter. In fact, you can perform any number of PHP operations before setting headers so long as you don't actually output any HTML before you set a header.
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#11886 Chapter 1, Sorting Multidimensional Arrays, Pg. 6 Function

Posted by Antonio Conte on 24 December 2012 - 11:55 PM

It compares all values in the array, but that happens internally. This is a pattern called a compator, and is used to compare collections structures like this PHP array (The array structure implements an Interface that makes it Comparable for a Comparator). To use more known examples, the reason why you can use a while loop on a MySQL(i) result object, is that this structure is built on a pattern called an iterator. This is also why arrays support foreach statements. (You can build this into your own classes)

This pattern is often tied to lists of objects in other languages. Let's say you have a Person class. A PersonList would be a class that handles a list of Person objects (Using an array internally). This class can have methods for looping, adding, removing, sorting and a lot of other things. Such classes are called a Collection in other languages, and is a definition for lists, (that's normal arrays in most languages) linkedLists, stacks, queques and other fun data structures, including Hash maps (associative array keys are implemented as a Hash map). In PHP, all of these data structures are defined as ARRAY........ Let that sink in.

The point here is that arrays in PHP is not arrays as you find them in other languages. That is not all bad, and also some of the reason why PHP is so awesome at times. The problem is that it makes it very hard to understand a lot of concepts for PHP developers as they don't understand the data structures strengths and weaknesses. Because we "have it all", very few developers has to think about how sorting, iterating and CRUD operations actually work.

The reason why your examples work is because of this. The standard, built in internal way of ordering arrays is by a method most often call compareTo() in other languages. This method could be implemented in the Person example class of ours through an interface often called Comparable. When that is done, the PersonList can easily compare each Person found in the list and thus sort the array of Person objects. What you basicly do here is to say that PHP's Array structure (A PersonList) should compare all keys called name found in an element (A Person), using either the standard compareTo function defined in the Element or a function you define yourself. (And that function then takes the job of the compareTo function instead)

This is both pretty advanced and pretty simple stuff at the same time. You cannot really understand all this at once, but that is approximaly how it should work. I cannot fully gurantee that's how PHP has actually implemented it, but these are well known patterns in object oriented programming. It can be defined as theory as much as implemented in practice. Once recommendation is to read about data structures if your interested, but if not then just take my word for it. Don't try to understand your toaster, just learn how to use it. ;)

Edit: Sorry about the poor English here, might clean it up a bit tomorrow. Been a great christmas with family, good food and a local liquor called "Akevit". (Aqua vita - water of life) It's a scandinavic speciality liquor that's great with fat food. Try it if you ever visit Denmark, Sweden or Norway. We take great pride in it, but mostly drink it around chirstmas time.
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#11512 Exception Handling For Flow Control?

Posted by Antonio Conte on 6 December 2012 - 6:46 PM

It depends. More often than not, application breaking errors should throw exception. As an example, an invalid date, improper email addresses or bad zip codes could benefit from throwing exceptions. The reason for that is data integrity. A class/function could very well be dependent of having valid data on a special format to be able to perform actions/calculations of it.

You'll often see people defining their own exceptions like so. In this example we have a example class for sending email. It's no point sending an email to "111lol!", so then it's good practice to throw an exception. (

class Email
public function send( $email )
    if (! filter_var($email, FILTER_VALIDATE_EMAIL))
	    throw new InvalidEmailAddressException("Invalid email adress provided.");

// Email exception
class InvalidEmailAddressException extends Exception
    public function __construct($message) { parent::__construct($message); }

Hope that gives you a general idea. Short answer would be this: for "checking values", use return values. User::add() could return true/false on how the adding went. For invalid values that could break classes/methods, throw exceptions.
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#11171 Php Code Allow Smartphone Applications (Iphone, Android) To Connect To My Web...

Posted by HartleySan on 18 November 2012 - 9:39 PM

If you want users to access your site from a web browser on their smartphone, then there is no additional code you need to write. The code would be the same for the desktop version and the smartphone version.
The only likely thing you'd want to change is making the smartphone version easier to view (than the desktop version) on a smartphone.

If, instead, you want to write a native app for iPhone and Android devices, then I suggest you by a book about how to write iPhone and Android apps (which use two separate languages), because PHP is not going to help you there.
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#10864 Require Usage For Constant

Posted by Antonio Conte on 1 November 2012 - 8:52 PM

Because it's just a constant holding a string. You need something called a resource, not a text string. A resource is created when the string (that is an URI to a script) is included, and the actual MySQL connection resource resource is created. The creation of this resource is happing inside the script you find by this URI.

Maybe things would be easier to understand if we did this in config.php:

$mysql = "path_to_connection_script.php";
$images = "path_to_image_folders";
define ('A_CONSTANT', "holding a string");

And a simple mysql script:
$mysql_resource = mysql_connect('mysql_host', 'mysql_user', 'mysql_password');
if ( ! $mysql_resource) {
die('Could not connect: ' . mysql_error());

And this was your script:
// Require config file holding variables and a constant
require 'config.php';

// Echo out the contents of the variable and constant
echo $mysql; // output: path_to_connection_script.php
echo A_CONSTANT; // output: holding a string

// Now require the resource
require $mysqli; // require 'path_to_connection_script.php';

// Now we have the mysql resource in $mysql_resource
$result = mysql_query($query, $mysql_resource); // Here we can use the resource to run a query

What this means is that a constant and a string is pretty much the same thing. The constant is just a way for you to centralize where to put the require paths for your scripts. You could just use something along:

define('MYSQL', 'path_to_connection_script.php');

// These two lines below are equal
require 'path_to_connection_script.php';
require MYSQL;

As you can see now, you are just getting this constant to use in your script. The whole point about a constant is that it is interchangeable. You can't define the same constant twice. This means that, if you require the config file, you are sure the MYSQL constant you find there will hold the value (an URI) needed for getting the mysql resource.

Edit: This may seem complicated, but a resource is only another data type like Strings (text) and integers (numbers). The whole point is that for running a query, you need the resource as it holds vital info for PHP internally. You don't really need to know how it works on the inside. The resource is simply created when calling the mysql_connect() function, and then you are ready to roll with queries.

Hope that helps.
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#10841 Require Usage For Constant

Posted by HartleySan on 31 October 2012 - 8:41 PM

I may be misunderstanding your question, but it seems like you are misunderstanding the meaning of the require function.
The require function does not redefine the constant MYSQL; it actually includes the file that is linked to by the string defined by the MYSQL constant.

The require function is similar to the include function in PHP, and both are used to basically drop all the code in the included file into the PHP script calling the include/require function at the exact point the function is called. For more details, please see the following:

As such, "require(MYSQL);" takes all the code in the file linked to by the string stored in the MYSQL constant (i.e., the database-connection script), and places all that code in your script at that point. More specifically, this require function executes the code in the DB-connect script and establishes a connection with the DB, which you can then use throughout the rest of the script.

Basically, if you want to access the DB anywhere in the script, you need to execute "require(MYSQL);" before that.

Does that answer your question?
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#10740 Paypal Integration Confusion

Posted by MrJames on 29 October 2012 - 7:14 AM


Try the following as an example:

<input type="hidden" name="amount" value=" ' . $productPrice . ' ">

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#10649 Advanced Question - What Is Happening In This For In Loop?

Posted by HartleySan on 24 October 2012 - 2:53 AM

When you ask for more "explicit" code to accomplish the same thing, I assume that you're really asking, "What's a simple way to accomplish the same thing?"

I'm not sure if there's a simpler way, as "simpler" code might actually be more confusing for a JS guru, but for demonstration purposes, I have put together some sample code that achieves the same thing without the use of closures (at least, not in the sense that you're thinking about) and without the use of the map method.

Keep in mind that my code is super simplistic, and I wouldn't actually recommend ever doing things this way, but for demonstration purposes, I think it serves its purpose well.

<!DOCTYPE html>

<html lang="en">


    <meta charset="UTF-8">

    <title>Chaining alternative</title>



    <a href="#" id="link1">Link 1</a>

    <a href="#" id="link2">Link 2</a>

    <a href="#" id="link3">Link 3</a>


      // this in these two functions is equal to the out array in function X.

      function color(x) {

        for (var i = 0; i < this.length; i++) {

          this[i].style.color = x;


        return this;


      function size(x) {

        for (var i = 0; i < this.length; i++) {

          this[i].style.fontSize = x;


        return this;


      function X(css) {

        var out = [];

        // For this simplified example, I'm assuming that css is always a tag name, not an ID.
        var tags = document.getElementsByTagName(css);

        for (var i = 0; i < tags.length; i++) {



        out['color'] = color;

        out['size'] = size;

        return out;






Does that help clarify things at all?

I know that that one guy's code on the other site is very difficult, so don't feel bad if it doesn't all click right away. He has a ton of complex code (and sometimes JS-specific idiosyncrasies) all stuck together.

To reply to your three points of interest:

1) Yes, scope in JS is very interesting. The thing about JS is that functions are lexically scoped, meaning that they contain the scope in which they're defined, not in which they are called. This is different from C, for example.

2) Yes, I agree that the way the length property is calculated in JS is interesting, but that's just the way it's defined in the ECMA specs (for better or worse). To give some more explanation, if an array contains only associative indexes, since that's akin to an object (not an array) in JS, the length will be 0. Another interesting caveat is that if, for example, you have an array with only 1 element, but the index of that element is 5, then the length will be reported as 6 (as per what I said in my previous post (i.e., 5 + 1)).

3) Closures are basically used as a tricky way to freeze a variable's state in time. For example, you may have a constantly changing global variable, but if you want to retain the value of that variable at one specific time, then you need to use a closure. Remember that every time a function is called, a closure is created (just usually not a closure in the sense that's commonly talked about). This happens because whenever a function is called, all the variables passed to that function are frozen in the state that they are in when the function was called. It's prudent to remember that this is NOT the case with function references/function definitions; only function calls. Anyway, for the m example, if you just remember that m is equal a specific instance of meths[meth] each time through the for-in loop, then you should be fine.

Hope that helps (and by all means, fire back another comment if it doesn't).
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#12215 When Js Isn'T Available.

Posted by HartleySan on 8 January 2013 - 6:24 PM

Unfortunately, that's the nature of the beast. With JS disabled, you lose a lot of functionality, and certainly, that's one if the downsides of relying on JS libraries to do all the work for you.

Obviously, you'd most likely want the non-JS version of your site to mirror the JS version as much as possible, but that's not always possible/practical. With that said, I think Larry says in one of his books somewhere, as long as the non-JS site works and gets the user the information necessary, that's good enough (even if the site looks/behaves like crap). I more or less agree with this, but obviously, if given the time, making a non-JS version of your site that is similar in appearance and functionality never hurts.

Here's my main COA when designing a site to have both a non-JS and JS version:

1) Plan, plan, plan! In regards to the above, this means trying to minimize JS as much as possible while still giving a good experience. By minimizing the JS used, the two sites will be more similar and it'll be less work to get both working correctly.
Unfortunately, if you're locked into something like Twitter bootstrap, then you might have your work cut out for you in this regard. This is one of the main things I don't like about a lot of JS libraries these days: they use JS for a lot of things you don't need JS for; nowadays, you can do a lot with HTML and CSS alone.

2) Use noscript tags for content that is required as a replacement for JS-generated content when JS is disabled. For example, you might make a new, second menu within noscript tags to handle navigation when your Twitter bootstrap menu is busted because JS is disabled.

3) For content that requires JS, either generate the markup for it using JS, or use CSS to hide the content by default, and then use JS to display it when the page first loads. If you don't do one or the other, then you will get JS-dependent content appearing on the screen, which is useless and confusing to users who have JS disabled (ala your Twitter menu).

4) With all the above in mind, develop the entire site first without using any JS. This will serve as a solid base. After that, add JS functionality as needed, keeping all the above in mind. Because this may be time-consuming, you may want to consider launching with the non-JS version only (since that should be enough to do whatever on your site), and then adding JS functionality here and there post-launch.

And that's basically it. Obviously, depending on the scope/size of your site, this may add considerable time to development, but that's the price you pay if you want a decent non-JS site. I think a log of people these days don't find it worth the effort to do all of the above though (so they don't).

And keep in mind that there are other things to consider these days as well. For example, "mobile first", which is a good guiding principle and strongly emphasizes loading content non-essential for the mobile version using JS. These sorts of considerations may very well conflict with designing a good non-JS site, so please keep that in mind.

Well, I've blabbered on long enough, and I probably mentioned a bunch of stuff you already knew, but there ya go.

- The other Jonathan (with a slightly different spelling)
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