I've got a simple question about variables in PHP!
How can i make a global final variable? I wanna have few information in a php-file. I've got some functions there who return the information.
<?php
static $titleOfPage = "Opinion";
static $autor = "Daniel";
static $description = "blablabla";
static $keywords = "blablabla";
function getTitleOfPage(){
return $titleOfPage;
}
function getAutorOfPage(){
return $autor;
}
function getDescriptionOfPage(){
return $description;
}
function getKeywordsOfPage(){
return $keywords;
}
?>
I include this file in another php file. And there i just wanna get the information from here. So when I do
echo getDescriptionOfPage();
I get the Error= Undefined variable: titleOfPage in /Applicat....
I only know the rules from C and JAVA..
Can anyone help me?
Thank you very much!
How can i make a global final variable?
So.. basically you want to define a named constant.
define("TITLE_OF_PAGE", "Opinion");
function getTitleOfPage(){
return TITLE_OF_PAGE;
}
But I'm pretty sure that there are no real reasons to do it. :P
Related
I recently made a class in PHP
I am trying to declare a variable within class and using str_replace in a function but its show undefined variable
class Status{
$words = array(".com",".net",".co.uk",".tk","co.cc");
$replace = " ";
function getRoomName($roomlink)
{
echo str_replace($words,$replace,$roomlink);
}
}
$status = new Status;
echo $status->getRoomName("http://darsekarbala.com/azadari/");
Any kind of help would be appreciated thanks you
Your variables in the function getRoomname() aren't adressed properly. Your syntax assumes the variables are either declared within the function or passed while calling the function (which they aren't).
To do this within a class, do it while using $this->, like this:
function getRoomName($roomlink)
{
echo str_replace($this->words,$this->replace,$roomlink);
}
For further informations, please have a look into this page of the manual.
Maybe because of the version or something, when I tested your exact code, I got syntax error, unexpected '$words' (T_VARIABLE), expecting function (T_FUNCTION), so setting your variables to private or public should fix this one.
About the undefined varible, you have to use $this-> to access them from your class. Take a look:
class Status{
private $words = array(".com",".net",".co.uk",".tk","co.cc"); // changed
private $replace = " "; // changed
function getRoomName($roomlink){
echo str_replace($this->words, $this->replace, $roomlink); // changed
}
}
$status = new Status;
echo $status->getRoomName("http://darsekarbala.com/azadari/");
Also, since getRoomName isn't returning anything, echoing it doesn't do much. You could just:$status->getRoomName("http://darsekarbala.com/azadari/");.
or change to :
return str_replace($this->words, $this->replace, $roomlink);
Is it possible to call only the specific function from another file without including whole file???
There may be another functions in the file and don't need to render other function.
The short answer is: no, you can't.
The long answers is: yes, if you use OOP.
Split your functions into different files. Say you are making a game with a hero:
Walk.php
function walk($distance,speed){
//walk code
}
Die.php
function die(){
//game over
}
Hero.php
include 'Walk.php';
include 'Die.php';
class Hero(){
//hero that can walk & can die
}
You may have other functions like makeWorld() that hero.php doesn't need, so you don't need to include it. This question has been asked a few times before: here & here.
One of the possible methods outlined before is through autoloading, which basically saves you from having to write a long list of includes at the top of each file.
In PHP it's not available to get only a little part of a file.
Maybe this is a ability to use only little parts of a file:
I have a class that calls "utilities". This I am using in my projects.
In my index.php
include("class.utilities.php")
$utilities = new utilities();
The file class.utilities.php
class utilities {
function __construct() {
}
public function thisIsTheFunction($a,$b)
{
$c = $a + $b;
return $c;
}
}
And then i can use the function
echo $utilities->thisIsTheFunction(3,4);
include a page lets say the function is GetPage and the variable is ID
<?php
require('page.php');
$id = ($_GET['id']);
if($id != '') {
getpage($id);
}
?>
now when you make the function
<?php
function getpage($id){
if ($id = ''){
//// Do something
}
else {
}
}
?>
im having trouble with my php program, it seems that my array variable being declared earlier wasn't detected in a function. Here's my code :
$msg = array(
//Errors List
'Error1' => 'Error 1',
'Error2' => 'Error 2'
);
//Class for outputting Messages
class Message {
static function Info($string) { echo $string; }
static function Error($string) { echo $string; }
}
//Functions
function function1($var1) {
if (!preg_match("/^[0-9]+$/", $var1)){
Message::Error($msg['Error1']);
}
when i run it, and example i test the program like this..
$test = 'blabla';
function1($test);
it says the msg variable was undefined. Can anyone tell me how to resolve this?
Thanks in advance.
There are three ways to solve this issue.
Passing the required global var as a parameter
In my opinion, this is the preferred solution, as it avoids the pollution of your function with global variables. Global variables tend to introduce unexpected side effects and make maintenance and reuse of code a lot harder. A very extensive article on why you should avoid globals whenever possible (and some alternative solutions) can be found in the c2 wiki
function function1($var1,$mesg) {
if (!preg_match("/^[0-9]+$/", $var1)){
Message::Error($mesg['Error1']);
}
}
The call to function1 changes to
function1($test,$msg);
Using global:
Same effect as the one just below, other notation.
function function1($var1) {
global $msg;
if (!preg_match("/^[0-9]+$/", $var1)){
Message::Error($msg['Error1']);
}
}
Using the $GLOBALS superglobal
Some sources say this form is slightly faster than the one using global
function function1($var1) {
if (!preg_match("/^[0-9]+$/", $var1)){
Message::Error($GLOBALS['msg']['Error1']);
}
}
you can not use $msg as a local variable in function.
function function1($var1) {
global $msg;
if (!preg_match("/^[0-9]+$/", $var1)){
Message::Error($msg['Error1']);
}
}
I want to validate a form with php.
Therefor I created a class "benutzer" and a public function "benutzerEintragen" of this class to validate the form:
class benutzer
{
private $username = "";
private $mail = "";
private $mail_check = "";
private $passwort = "";
private $passwort_check = "";
public $error_blank = array();
public $error_notSelected = array();
public $error_notEqual = array();
public function benutzerEintragen () {
$textfields[0] = $this->username;
$textfields[1] = $this->mail;
$textfields[2] = $this->mail_check;
$textfields[3] = $this->passwort;
$textfields[4] = $this->passwort_check;
foreach ($textfields as $string) {
$result = checkFormular::emptyVariable($string);
$error_blank[] = $result;
}
In the function "benutzerEintragen" i filled the variables "username,mail" and so on with the appropriate $_POST entries (not shown in the code above). The call
checkFormular::emptyVariable($string)
just returns "TRUE" if the field is not set or empty otherwise FALSE.
Now when i try to create a new instance of this class, execute the function and get access to $error_blank[0] the array is empty!
if (($_SERVER['REQUEST_METHOD'] == 'POST')){
$BENUTZER = new benutzer();
$BENUTZER->benutzerEintragen();
echo $BENUTZER->error_blank[0];}
So the last line is leading to a "Notice: Undefined offset: 0". It seems to be related to the array structure, because if i do
echo $BENUTZER->mail;
I get any input I wrote in the form, which is correct. Also the foreach loop seems to do the right thing when i run the debugger in phpEd, but it seems like the array "error_blank" is erased after the function is executed.
Any help would be greatly appreciated. Thanks in advance.
There is a scope problem here. You do have a class attribute with the name. Unlike in Java where using a local variable with the same name as a class variable automatically selects the class attribute this is not the case in PHP.
Basically you are saving your output in a local variable which gets discarded once you leave the function. Change $error_blank[] = $result; to $this->error_blank[] = $result; and you should be fine.
First of all this seems overly complicated way to do a simple task, but that wasn't actually the question.
You are creating a new $error_blank variable that is only in function scope. If you wish to use the class variable you should use $this->error_blank[]
I am trying to assign a variable to a class in PHP, however I am not getting any results?
Can anyone offer any assistance? The code is provided below. I am trying to echo the URL as shown below, by first assigning it to a class variable.
class PageClass {
var $absolute_path = NULL;
function get_absolute_path(){
$url = $this->absolute_path;
echo $url;
}
}
$page = new PageClass();
$page->absolute_path = "http://localhost:8888/smile2/organic/";
$page->get_absolute_path(); //this should echo the URL as defined above - but does not
It also works for me.
Take a look at a live example of your code here.
However, there are a few things you should change about your class.
First, Garvey does make a good point that you should not be using var. That's the older PHP4, less OOP conscious version. Rather declare each variable public or private. In fact, you should declare each function public or private too.
Generally, most classes have private variables, since you usually only want to change the variables in specific ways. To achieve this control you usually set several public methods to allow client functions to interact with your class only in restricted predetermined ways.
If you have a getter, you'd probably want a setter, since these are usually used with private variables, like I described above.
A final note is that functions named get usually return a value. If you want to display a value, it is customary to use a name like display_path or show_path:
<?php
class PageClass
{
private $absolute_path = NULL;
public function set_absolute_path($path)
{
$this->absolute_path = $path;
}
public function display_absolute_path()
{
echo $this->absolute_path;
}
}
$page = new PageClass();
$page->set_absolute_path("http://localhost:8888/smile2/organic/");
$page->display_absolute_path();
// The above outputs: http://localhost:8888/smile2/organic/
// Your variable is now safe from meddling.
// This:
// echo $this->absolute_path;
// Will not work. It will create an error like:
// Fatal error: Cannot access private property PageClass::$absolute_path on ...
?>
Live Example Here
There's a section on classes and objects in the online PHP reference.
class PageClass {
public $absolute_path = NULL;
function get_absolute_path(){
$url = $this->absolute_path;
return $url;
}
}
$page = new PageClass();
$page->absolute_path = "http://localhost:8888/smile2/organic/";
echo $page->get_absolute_path();
Works fine for me.
Have you checked that the script and esp. the code in question is executed at all?
E.g. add some unconditional debug-output to the script. Or install a debugger like XDebug to step through the code and inspect variables.
<?php
class PageClass {
var $absolute_path = NULL; // old php4 declaration, see http://docs.php.net/oop5
function get_absolute_path() { // again old php4 declaration
$url = $this->absolute_path;
echo "debug: "; var_dump($url);
echo $url;
}
}
$page = new PageClass();
$page->absolute_path = "http://localhost:8888/smile2/organic/";
echo "debug: page->get_absolute_path\n";
$page->get_absolute_path();