Just wondering, do $_GET and $_POST still work properly in php7? Or do they actually work in a different way than in the old one?
I try to make this code work in a way it returns param 2 when the page url reads do = update at some point, but it didn't. Can someone help me?
<?php
if (isset($_GET['do']) == "update") {
$param=2;
}
else{
$param=1;
}
?>
I assume I am supposed to redirect to a certain page when $param=2 after this link is clicked
Update
$_GET and $_POST still works. Your conditional doesn't, should be :
if (isset($_GET['do']) && $_GET['do'] == 'update') {
$param = 2;
} else {
$param = 1;
}
(as a fun note, can be simplified to):
$param = (isset($_GET['do']) && $_GET['do'] == 'update' ? 2 : 1);
No there's no change to this functionality in PHP7. These variables are fundamental to interacting with HTTP, they can't really change unless that standard changes. Anyway it's nothing to do with that, you simply made a nonsensical comparison:
isset($_GET['do'])
will return either true or false. If it's false it will never be equal to the string "update". If it's true it might by equal by accident because you used == instead of ===. But either way it makes no logical sense to try and compare them. It's not a useful comparison
This code is probably more like you were intending:
<?php
$do = $_GET['do'];
if(isset($do)) //only continue if the variable is definitely set
{
if ($do == "update")
{
$param = 2;
}
else
{
$param = 1;
}
}
else
{
//do something else if the variable is not even set - perhaps an error?
}
?>
Or maybe you wanted to set $param = 1 in all cases except when "do" is set to "update". Your intent is not 100% clear, but the point is your that if statement is wrong.
Related
if(!isset($_GET['new_quiz']) || !isset($_GET['view_quiz']) || !isset($_GET['alter_quiz'])){
echo "No";
}
else{ echo "Yes"; }
When I go to index.php?view_quiz, it should give result as Yes, but it results as No. Why?
My Other Tries:
(!isset($_GET['new_quiz'] || $_GET['view_quiz'] || $_GET['alter_quiz']))
( ! ) Fatal error: Cannot use isset() on the result of an expression
(you can use "null !== expression" instead) in
C:\wamp\www\jainvidhya\subdomains\teacher\quiz.php on line 94
(!isset($_GET['new_quiz'],$_GET['view_quiz'],$_GET['alter_quiz']))
NO
You may find than inverting the logic makes the code easier to read, I also like to have a more positive idea of conditions as it can read easier (rather than several nots means no).
So this says if anyone of the items isset() then the answer is Yes...
if(isset($_GET['new_quiz']) || isset($_GET['view_quiz']) || isset($_GET['alter_quiz'])){
echo "Yes";
}
else{ echo "No"; }
Note that I've changed the Yes and No branches of the if around.
You are probably looking for
if(!isset($_GET['new_quiz']) && !isset($_GET['view_quiz']) && !isset($_GET['alter_quiz'])){
echo "No";
}
else {
echo "Yes";
}
which will print Yes if none of new_quiz, view_quiz and alter_quiz are present in the URL. If this is not your desired outcome, please elaborate on your problem.
#paran you need to set a value for view_quiz=yes for example
if(!isset($_GET['new_quiz']) || !isset($_GET['view_quiz']) || !isset($_GET['alter_quiz'])){
echo "No";
}
else{ echo "Yes"; }
and the url
index.php?new_quiz=yes
index.php?view_quiz=yes
index.php?alter_quiz=yes
All Will return true
isset()allows multiple params. If at least 1 param does not exist (or is NULL), isset() returns false. If all params exist, isset() return true.
So try this:
if( !isset( $_GET['new_quiz'], $_GET['view_quiz'], $_GET['alter_quiz']) ) {
First, to answer your question:
When I go to index.php?view_quiz, it should give result as Yes, but it results as No. Why?
This is becaue this
if(!isset($_GET['new_quiz']) || !isset($_GET['view_quiz']) || !isset($_GET['alter_quiz'])){
checks if either one of your parameter is not set, which will always be the case as long as you are not setting all three parameter simultaneously like this:
index.php?alter_quiz&view_quiz&new_quiz
As #nigel-ren stated, you may wan't to change that logic to
if(isset($_GET['new_quiz']) || isset($_GET['view_quiz']) || isset($_GET['alter_quiz'])){
echo 'Yes';
which checks if at least one parameter is set.
If you wan't to check if there is only one of the three parameters set, you would have to work with XOR (which is slightly more complicated)
$a = isset($_GET['new_quiz']);
$b = isset($_GET['view_quiz']);
$c = isset($_GET['alter_quiz']);
if( ($a xor $b xor $c) && !($a && $b && $c) ){
echo 'Yes';
(based on this answer: XOR of three values)
which would return true if one and only one of the three parameters is set.
But - and this is just an assumption, please correct me if I'm wrong - I think what you are trying to achieve are three different pages (one for creating a quiz, one for viewing it and one for editing it). Therefore, you will likely run into a problem with your current setup. For example: What would happen if a user calls the page with multiple parameters, like
index.php?alter_quiz&view_quiz
Would you show both pages? Would you ignore one parameter? I would recommend to work with a single parameter to avoid this problem in the first place. For example site which can take the values alter_quiz, view_quiz or new_quiz. E.g.:
index.php?site=alter_quiz
Then you can work like this:
// check if site is set before getting its value
$site = array_key_exists( 'site', $_GET ) ? $_GET['site'] : NULL;
// if it's not set e.g. index.php without parameters is called
if( is_null($site) ){
// show the start page or something
}else{
$allowed_sites = ['new_quiz', 'view_quiz', 'alter_quiz'];
// never trust user input, check if
// site is an allowed value
if( !in_array($site, $allowed_sites, true) ){
die('404 - This site is no available');
}
// here you can do whatever your site should do
// e.g. include another php script which contains
// your site
include('path/to/your/site-' . $site . '.php');
// or echo yes
echo 'Yes';
}
I am in a very puzzling situation. Intially when an user visits a particular page, a popup is shown. User can accept it or decline it. When a user declines it, after 5 page visits, the pop up is again shown to user. This part is working perfectly. When user clicks ok, an ajax call is made and the SESSION variable is set to ok. Lets say initially $_SESSION['count'] = 0. I have two condition statements.
if($_SESSION['count']%5 === 0)
{ // do something
}
elseif($_SESSION['count'] === "ok")
{ // do something
}
Now when an user press ok, an ajax call is made updating $_SESSION['count'] = "ok".
When the user again reloads the page, condition if($_SESSION['count']%5 === 0) gets true even though $_SESSION['count'] is now ok. Later after much experimenting, i came to know that in php i am able to divide or find modulus string by number which will result in zero. How can i handle this?
You can use is_numeric to check if it is a count or 'ok'
http://php.net/manual/en/function.is-numeric.php
if(is_numeric($_SESSION['count']) && $_SESSION['count']%5 === 0)
{ // do something
}
elseif($_SESSION['count'] === "ok")
{ // do something
}
Though generally, I would set ok to be the value of a different variable in $_SESSION as a best practice. If I was looking at the code I would find it very odd to see something called count having a string value.
PHP is very good at implicit casting.
A solution to your issue is simply re-arrange your if else tree.
if($_SESSION['count'] === "ok")
{
// do something
}
elseif($_SESSION['count'] % 5 === 0)
{
// do something
}
Readability
Something to bare in mind, is that a variable count should really contain a value. Perhaps using a different variable might make your code a little less confusing to a reader.
In php, (int) "some string" == 0, so check if $_SESSION['count'] is an integer (e.g. using is_numeric()) before doing the modulus.
Check this working example. It may help:
if(!isset($_SESSION['foo'])) {
$_SESSION['foo'] = 0;
} else {
$_SESSION['foo']++;
}
var_dump($_SESSION['foo']%3);
if(is_numeric($_SESSION['count']) AND $_SESSION['count']%5 === 0)
{ // do something
}
elseif($_SESSION['count'] === "ok")
{ // do something
}
dispatch_address_postcode
isn't mandatory and it will still run even if it's blank:
if (!is_null($_POST['personal_info_first_name']) &&
!is_null($_POST['personal_info_surname']) &&
!is_null($_POST['personal_info_email']) &&
!is_null($_POST['personal_info_telephone']) &&
!is_null($_POST['dispatch_address_country']) &&
!is_null($_POST['dispatch_address_first_name']) &&
!is_null($_POST['dispatch_address_surname']) &&
!is_null($_POST['dispatch_address_address']) &&
!is_null($_POST['dispatch_address_town']) &&
!is_null($_POST['dispatch_address_postcode']) &&
!is_null($_POST['dispatch_address_county']) &&
( ($_POST['payment_method'] == "Pay by credit card.") ||
(
($_POST['payment_method'] == "Pay by new credit card.") &&
!is_null($_POST['card_number']) &&
!is_null($_POST['expiration_date']) &&
!is_null($_POST['security_code'])
)
)
)
What gives?
"dispatch_address_postcode isn't mandatory and it will still run even if it's blank…"
Just look at that sentence again. If the field is not mandatory, it is perfectly okay if the code runs if the field is blank. If a field isn't mandatory, don't test it as mandatory.
The real problem is though, is_null only tests if the variable is null. POSTed values will never be null, if they're empty they will be '' (an empty string). All your !is_null tests will always be true, and you will get a warning if the variable isn't set (something you don't want to happen). The more appropriate test would be !empty.
Even more appropriate tests would include a test if the value appears to be valid (does email look like an email address, does telephone have at least x digits in it?). You should also loop through the fields to make your code more readable, endless nested and chained if conditions are no joy to look at.
$mandatoryFields = array('foo' => 'email', 'bar' => 'telephone');
foreach ($mandatoryFields as $field => $rule) {
if (empty($_POST[$field]) || !validateByRule($_POST[$field], $rule)) {
raiseHell();
}
}
It looks like you're trying to make sure all post variables are submitted. Would you like help with that?
Using !empty() may not be the answer to your specific question, but it would definitely help with what it looks like you're trying to do.
empty() returns TRUE if the $_POST key isn't set, if its an empty array, or even if its an empty string, so using !empty() is a good way to make sure that the user has filled in the information.
Try writing your own is_valid function and use that rather than is_null.
For example (and this is by no means comprehensive):
function is_valid(&$array, $key, $required=false) {
if(!array_key_exists($array))
return false;
$value = trim($array[$key]);
if(empty($value) && $required)
return false;
return true;
}
Use like so:
if(is_valid($_POST, 'personal_info_first_name', true) && ...)
!is_null($_POST['personal_info_first_name']) && !isset($_POST['personal_info_first_name'])
use array_key_exists('card_number', $_POST) && !empty($_POST['card_number'])
Edit: Please consider this before a downvote. I'm leaving this here to serve as a "what not to do". I would delete it because it's bad, but then nobody would learn from my mistakes.
DO NOT DO THIS - read the comments for great info on why this is bad
My answer is going to be wildly different, but I am a wildly different guy...
I JUST found that this will work. Instead of all that isset and things, just assign the variables programmatically! I think I have some refactoring to do... y'know on all my code...
if (!is_array($_POST)){exit "$_POST isn't an array";}
foreach ($_POST as $param => $value){
${$param} = secure($value);
}
//now you have a set of variables that are named exactly as the posted param
//for example, $_POST['personal_info_first_name'] == $personal_info_first_name
if ($payment_method == "Pay by credit card."){
//do stuff that you were gonna do anyways
} else if ($payment_method == "Pay by new credit card.") {
if ($card_number && $expiration_date && $security_code){
//do stuff that you were gonna do anyways
} else {
exit("info missing for credit card transaction");
}
} else {
exit("unknown payment method")
}
function secure($input){
//sanitize user input
}
If you use this code, then it doesn't matter what is null and what isn't within the foreach because anything that's null just won't be made. Then you can use nicer looking code (and probably faster code) to check for anything that is required.
I have a basic PHP question, take the code below for example, let's say I need to use this 10 times on a page, is there a better way to do it?
I realize I could wrap it in a function and just keep calling that function but is there a better way then to keep on checking if the item is set and equals a a certain value. After finding this out the first time is there some other way of remembering the result from the first time instead of doing it 10 different times?
Hope that makes sense.
<?PHP
if (isset($_SESSION['auto_id']) && $_SESSION['auto_id'] == "1") {
//do something
}
// do other code here that breaks these up
if (isset($_SESSION['auto_id']) && $_SESSION['auto_id'] == "1") {
//do something else
}
// do other code here that breaks these up
if (isset($_SESSION['auto_id']) && $_SESSION['auto_id'] == "1") {
//do something else
}
// do other code here that breaks these up
if (isset($_SESSION['auto_id']) && $_SESSION['auto_id'] == "1") {
//do something else
}
...ect
?>
In this case, yes you have to, although you could do it once and assign the result to a variable.
how about...
<?PHP
$myCheck = (isset($_SESSION['auto_id']) && $_SESSION['auto_id'] == "1") ;
if($myCheck) {
//do something
}
// do other code here that breaks these up
if($myCheck) {
//do something else
}
// do other code here that breaks these up
if($myCheck) {
//do something else
}
// do other code here that breaks these up
if($myCheck) {
//do something else
}
etc.
?>
Syntax may be off - it's a long time since I've done any PHP work...
Sure. Just save the value of the boolean expression in another variable.
<?php
$auto_id_is_one = ($_SESSION['auto_id']) && $_SESSION['auto_id'] == "1");
// ...
if ($auto_id_is_one) {
// do something
}
// ...
if ($auto_id_is_one) {
// do something else
}
// ...
?>
You probably want to give it a more meaningful name than $auto_id_is_one, though.
Maybe a better approach is to use isset once at the top of the function, and set the variable to a default value there. Then you can simply use the value through the rest of the function.
In your example, you could set it to "0", though I realize that may not be the real code...
It depends what the "do something" block of code is, and whether or not the auto_id index of $_SESSION is changed in the other code. You can be certain that, in the body of the first if, the variable exists and is 1. Once that if concludes, you can no longer be certain - you'll have to check again later unless all the rest of the code is executed in a context that only exists if the first test succeeds (i.e. there's an else clause that terminates the script), and you are sure you don't change the value (and no external code you call changes it).
A better way to check the sanity might be to ensure most of the environment is as you expect it just once, then just check specific values at various places. However, if you're constantly rechecking this, it might indicate a design flaw, where similar logic (i.e. that dependent on auto_id = 1) is not well isolated and grouped.
In the example you provided, PHP will just issue an E_NOTICE that the index is not found in the $_SESSION super global (It will not throw the notice if you turned off strict mode). The best practice would be to go and set the value to a default so that you know for sure that the variable is set.
ex
<?php
$myVar = isset($_SESSION['auto_id']) ? $_SESSION['auto_id'] : FALSE;
if (false !== $myVar)
{
//do something
}
//do something not realated to myVar being set
if (false !== $myVar)
{
//do somethign else
}
?>
<?PHP
if (isset($_SESSION['auto_id']) && $_SESSION['auto_id'] == "1") {
$sessionOK = TRUE;
}
if ($sessionOK) {
//do this
}
if ($sessionOK) {
//do that
}
Below is a snippet of PHP that I need to get working, I need to make sure that 3 items are not set already and not === ''
I have the part to make it check if not set but when I try to see if the values are empty as well (I might not even be thinking clearly right now, I might not need to do all this) But I need to make sure that redirect, login_name, and password are all not already set to a value, if they are set to a value I need to make sure that the value is not empty.
Can someone help, when I add in check to see if values are empty, I get errors with my syntax, also not sure if I should have 5-6 checks like this in 1 if/else block like that, please help
I need to check the following:
- $_GET['redirect'] is not set
- $_REQUEST['login_name'] is not set
- $_REQUEST['login_name'] is not != to ''
- $_REQUEST['password'] is not set
- $_REQUEST['password'] is not != to ''
if (!isset($_GET['redirect']) && (!isset($_REQUEST['login_name'])) && (!isset($_REQUEST['password']))){
//do stuff
}
UPDATE
Sorry It is not very clear, I was a bit confused about this. Based on Hobodaves answer, I was able to modify it and get it working how I need it. Below is the code how I need it, it works great like this... So if that can be improved then that is the functionality that I need, I just tested this.
if (!isset($_GET['redirect'])
&& empty($_GET['redirect'])
&& isset($_REQUEST['login_name'])
&& !empty($_REQUEST['login_name'])
&& isset($_REQUEST['password'])
&& !empty($_REQUEST['password'])
) {
echo 'load user';
}
if this was loaded then it will run the login process
login.php?login_name=test&password=testing
If this is loaded then it will NOT run the login process
login.php?login_name=test&password=
if (!isset($_GET['redirect'])
&& !isset($_REQUEST['login_name'])
&& empty($_REQUEST['login_name'])
&& !isset($_REQUEST['password'])
&& empty($_REQUEST['password'])
) {
// do stuff
}
This is exactly what you describe, (not != empty === empty). I think you should edit your question though to explain what you're triyng to do, so we can suggest better alternatives.
Edit:
Your updated question can be simplified as:
if (empty($_GET['redirect'])
&& !empty($_REQUEST['login_name'])
&& !empty($_REQUEST['password'])
} {
// load user
}
A more maintainable solution would be storing each key in an array, and then foreach over it and check if isset or empty. You're not very DRY with your current solution.
The implementation would look someting like:
<?php
$keys = array('login_name', 'password');
foreach($keys as $key)
{
if(!isset($_REQUEST[$key]) || empty($_REQUEST['key'])
// Show error message, kill script etc.
}
// Dot stuff
?>
If a global variable is not set, that is the same as being empty. Thus:
!is_set(($_REQUEST['username'])) is the same as empty($_REQUEST['username'])
So based on your update, you can simplify to:
if (empty($_GET['redirect'])
&& !empty($_REQUEST['login_name'])
&& !empty($_REQUEST['password'])
) {
echo 'load user';
}
please read!
Sorry, the previous answer I gave will not give you what you want. Here is why:
If you use !_REQUEST['password'], it will return true if the password is empty or if it is not set. However if you use if($_REQUEST['password']) it will pass the conditional anytime that global variable is set, even if it is empty.
Therefore I recommend:
$no_redirect = (!$_GET['redirect']);
$login_name = (!$_REQUEST['login_name']) ? false : true;
$password = (!$_REQUEST['login_name']) ? false : true;
if($no_redirect && $login_name && $password) {
echo 'load user';
}
Sorry for the previously bad info.
You could create an array
$array = array(
$_GET['redirect'],
$_GET['redirect'],
$_REQUEST['login_name'],
$_REQUEST['login_name'],
$_REQUEST['password'],
$_REQUEST['password']
);
foreach($array as $stuf)
{
if(!empty($stuff) && $tuff !=0)
//do something
}