When I use the || (OR) operator in my if statement below I end up in an endless loop.
For sake of simplicity here is the var_dump:
$auth "0"
$id "2"
$enabled "1"
$page "auth-login.php"
If the criteria below is not met in the if statement then it will forward the user to auth-login.php (this is not applicable if the current $page is auth-login.php and auth-login-validate.php).
Statement without || (OR) operator: Forwards to auth-login.php as intended, but must also include auth-login-validate.php
if ($auth == '0' && $id != '1' && $enabled == '1' && $page != 'auth-login.php') {
header('Refresh: 0; URL=auth-login.php');
die();
}
Statement with || (OR) operator: Forwards to auth-login.php endlessly in a loop.
if ($auth == '0' && $id != '1' && $enabled == '1' && $page != 'auth-login.php' || $auth == '0' && $id != '1' && $enabled == '1' && $page != 'auth-login-validate.php') {
header('Refresh: 0; URL=auth-login.php');
die();
}
Will be some precedence related error. Make sure to put the parentheses where you intend to encapsulate the "OR" parts
Related
This seems pretty simple, but I can't figure that out.
I am checking a few variables before showing some stuff on the screen, and I have a variable which can be null at some point.
On my if statement I have:
if ($a != 'abc' && ($a == $b || $b == $c) && min($variable) > 3) { ... }
How can I set it true if min($variable) is null, if all the other statements are true?
As I understood from your question,
the min($variable) maybe null and you want to check it whether it's value less than 3 or null value ?
if ($a != 'abc' && ($a == $b || $b == $c)
&& (min($variable) > 3 || min($variable) == null)) { ... }
could be using a ternary operator inside ( )
if ($1 != 'abc' && ($1 == $2 || $2 == $3) &&
( $variable == null ? true : min($variable) > 3) ) { ... }
I am attempting to use both AND and OR statements in my IF/ELSE statement, but I cannot get the desired effect.
What I would like to achieve is that if either 'a' or 'b' has a value of '1' but both 'c' and 'd' must be 1 then I get 'Yes'.
All my attempts have given me either 'Yes' or have not worked (blank screen).
<?php
$a = "0";
$b = "1";
$c = "1";
$d = "1";
if (($a == "1") || ($b == "1") && ($c == "1") && ($d == "1")) {
echo "Yes";
}
else {
echo "No";
}
?>
Thank you.
You need and extra parenthesis, to make sure the evaluation order will be done correctly, like in math:
if ( ( ($a == "1") || ($b == "1") ) && ($c == "1") && ($d == "1")) {
^ ^
That way, let's say for example:
$a = 1;
$b = 2;
$c = 1;
$d = 2;
The first parenthesis will be evaluated as true || false. The final result will be true.
So now you have true && ($c == "1") && ($d == "1")
$c = 1, so again, the next evaluation will be true && true && ($d == 1)
$d = 2, so the next round will be true && true && false, final result, in this example, will be false.
You need to add parenthesis.
Why?
Because inner parenthesis are evaluated first before outer parenthesis. Take this example:
((1 == 1 && (2 == 2)) || 3 == 3)
What will be evaluated first? The 2 == 2 then the 1 == 1 and then the 3 == 3. In your if condition, because you are mixing AND's and OR's, you will not get the desired affect.
( (($a == "1") || ($b == "1")) && ($c == "1") && ($d == "1") )
Should work for you. In fact you can do this so that it looks even better:
(($a == 1 || $b == 1) && $c == 1 && $d == 1)
Because it is not necessary to put 1 in quotes ie: "1". PHP's truthiness will evaluate 1 == "1" to be true. However if you wanted to check for an actual string that contains 1, then you would use the === operator.
$a = 1;
$b = "1"
$a == "1"; // true
$b == 1; // true
$a === "1"; // false
$b === "1"; // true
However for more information go here: http://php.net/manual/en/language.operators.precedence.php
The equality operators will be evaluated first, then &&, then ||. Parentheses will be evaluated before anything else, so adding them can change the order.
Check the answer In Java, what are the boolean "order of operations"?
It will always echo a Yes because PHP interpreter places The AND operation before the OR operation.
So your if statement interpretes like this:
If
a = 1 or b = 1 and c = 1 and d = 1
then
echo 'Yes'
else
echo 'No'
That's why you always get a yes..
I'm using PHP's preg_match to help determine the value of a string.
But the code only ever prints 1 or 2.
Why aren't the last two cases of my if statement ever matched?
$atype = strtolower($userData['user_type']); // let say data is :: company introducer
if ($atype == "individual introducer" || $atype == "individualintroducer" ||
(preg_match('/i/',$atype) AND preg_match('/int/',$atype)) ) {
$atype = 1 ;
} elseif ($atype == "individual investor" || $atype == "individualinvestor" ||
(preg_match('/i/',$atype) AND preg_match('/inv/',$atype)) ) {
$atype = 2;
} elseif ($atype == "company introducer" || $atype == "companyintroducer" ||
(preg_match('/c/',$atype) AND preg_match('/int/',$atype)) ){
$atype = 3;
} elseif ($atype == "company investor" || $atype == "companyinvestor" ||
(preg_match('/c/',$atype) AND preg_match('/inv/',$atype)) ){
$atype = 4;
}
echo $atype;
You need to explain your question in a better way.
But i guess as you say the data assumed is company introducer.
So it already matches condition for the first if block.
For ex:
In company introducer
The preg_match will return true.
if($atype == "individual introducer" || $atype == "individualintroducer" || (preg_match('/i/',$atype) AND preg_match('/int/',$atype)) ){
$atype =1 ;
}
I've this situation in code where i think the code is unnecessary complex and i believe i can refactor it to make it more easier to understand and read.
So i googled about it and found decompose conditional refactoring, but i'm still in doubt how to do refactoring
if(count($bagTypes) == 1 && (array_key_exists('type1', $bagTypes)
|| array_key_exists('type2', $bagTypes)
|| array_key_exists('type3', $bagTypes))){
$flag = 1;
}
if(count($bagTypes) == 2 && (
(array_key_exists('type1', $bagTypes) && array_key_exists('type2', $bagTypes)) ||
(array_key_exists('type1', $bagTypes) && array_key_exists('type3', $bagTypes)) ||
(array_key_exists('type2', $bagTypes) && array_key_exists('type3', $bagTypes)))
){
$flag = 1;
}
Is there any better way of doing this?
You could try something like this:
$arrayKeys = array(
'type1',
'type2',
'type3'
);
$bagTypesKeys = array_keys($bagTypes);
if ((count($bagTypes) == 1 && count(array_diff($arrayKeys, $bagTypesKeys)) < 3)
|| (count($bagTypes) == 2 && count(array_diff($arrayKeys, $bagTypesKeys)) < 2))
{
$flag = 1;
}
I'm creating a custom search form and when I try and sort the results I get all the objects displayed instead of the matched criteria. The reason I discovered was that some of the inputs from the form don't have a default value and when this is not declared in the conditional statement later on (for sorting) it just shows all the objects, whether the other requirements are met or not. I tried applying an OR statement with the specific variables able to be empty, but it gave the same result. Like so -
<?php if ($bedrooms >= $min_rooms
&& $bedrooms <= $max_rooms
&& $space >= $min_space
&& $space <= $max_space
&& $price >= $min_price
&& $price <= $max_price
&& $sel_type == $type
|| $sel_type == ''
&& $country == $sel_country
|| $sel_country == '' ) { ?>
(See the last two statements)
I was thinking of checking each variable in the conditional statement before including it but it feels like unnecessary code. How would you do it?
The && operator has a higher precedence than the || operator, so your expression is currently grouped like this, probably not what you want:
($bedrooms >= $min_rooms && $bedrooms <= $max_rooms && $space >= $min_space && $space <= $max_space && $price >= $min_price && $price <= $max_price && $sel_type == $type)
||
($sel_type == '' && $country == $sel_country)
||
($sel_country == '' )
Try adding parentheses like this to achieve correct grouping:
($bedrooms >= $min_rooms && $bedrooms <= $max_rooms && $space >= $min_space && $space <= $max_space && $price >= $min_price && $price <= $max_price && ($sel_type == $type || $sel_type == '') && ($country == $sel_country || $sel_country == '') )
Your expression may fail as the && operator has a higher precedence than the || operation. That means an expression like this:
… && $sel_type == $type || $sel_type == ''
is equivalent to this (operator precedence highlighted by using parentheses):
(… && $sel_type == $type) || $sel_type == ''
To fix that put the || expressions in parentheses:
$bedrooms >= $min_rooms && $bedrooms <= $max_rooms && $space >= $min_space && $space <= $max_space && $price >= $min_price && $price <= $max_price && ($sel_type == $type || $sel_type == '') && ($country == $sel_country || $sel_country == '')
Additionally, your expression is probably easier to read and to maintain if you use some helper functions like a between function:
function between($val, $min, $max) {
return $min <= $val && $val <= $max;
}
Then your expression reads:
between($bedrooms, $min_rooms, $max_rooms) && between($space, $min_space, $max_space) && between($price, $min_price, $max_price) && ($sel_type == $type || $sel_type == '') && ($country == $sel_country || $sel_country == '')