I am new to PHP and find it very hard to explain.
I have a PHP navigation script with 5 categories and two variables relevant to my question:
$catname = 'used-cars'; // the same value for all categories
$currentpage; // pages 1 to 5
index.php of my site has $currentpage == '1'
The issue is that I need a logic that will say:
If $catname IS NOT 'used-cars', do something, BUT, IF $currentpage is equal to 1, even if $catname is 'used-cats' do it anyway
I am thinking of something like this:
if($catname != 'used-cars' && !($currentpage > '1')):
endif;
Hope you can help!
This is merely a single or condition. On the right side, $currentpage === 1 will evaluate to TRUE without regard to the value of $catname. If either part of the condition is TRUE, you'll enter the if () block to execute your code there.
if ($catname !== "used-cars" || $currentpage === 1) {
// do your thing
}
This is just:
if (strcmp($catname, 'used-cars') != 0 || $currentpage == 1)
(Careful with the string comparison.)
Alternatively, you could declare it as a boolean first:
$proceed = false;
if($catname != 'used-cars')
$proceed = true;
if($currentpage == 1)
$proceed = true;
if($proceed){
// whatever you want
}
$doflag = 0;
if($catname != 'used-cars')
{
$doflag = 1;
} else if($currentpage == 1) {
$doflag = 1;
}
if($doflag == 1) {
//do something
}
Basically instead of trying to do everything with the block, use the block to set a flag and use the flag to do something.
Related
I am sorry to ask such a question but am bit confused about this.
I am having simple variables defined.
$a =1;
$b=2;
$c=3;
$d="";
for($i=0;$i<10;$i++)
{
$testa = 1;
$testb = 4;
$testc = 3;
$testd = 7;
if($a!="" || $b!="" || $c!="" || $d!="") {
if($a==$testa && $b==$testb && $c==$testc && $d==$testd) {
echo $testa;
echo $testb;
echo $testc;
echo $testd;
}
}
}
This is sample php code.
what I need is that I have variables defined at top. SO in my loop i want to display result if user has any 1 variable but in below loop display result based on "and" parameter.
I actually want to skip the empty variable. SO in this case, I want as $d is empty, so it should be prevented somehow from if($a==$testa && $b==$testb && $c==$testc && $d==$testd) from here.
Any help is really appreciated.
To skip the empty values from the check, use ||
if ( ... && (empty($d) || $d == $testd)) {
Then if you also want to skip it in your echos :
echo !empty($d) ? $testd : '';
I have string $a,$b,$c
I know if all of them not null express in this way:
if($a!="" && $b!="" && $c!="")
But if either 2 of them not null then go into the true caluse
if($a!="" && $b!="" && $c!=""){
** do the things here **
}else if(either 2 are not null){
**do another things here**
}
How to express it?
I would write a simple function like this to check:
function checkInput($var)
{
$nulls=0;
foreach($var as $val)
{
if(empty($val))
{
$nulls++;
}
}
return $nulls;
}
Then access it like this:
$inputs=array($a, $b, $c.... $z);
$nullCount=checkInput($inputs);
if($nullCount==0)
{
// All nulls
}
if($nullCount>2)
{
// More than 2 nulls
}
or for an one-off test, just pop the function into the actual if statement like this:
if(checkInput($inputs)>2)
{
// More than 2 nulls...
}
etc etc. You can then use the one function to check for any number of nulls in any number of variables without doing much work - not to mention change it without having to rewrite a long if statement if you want to modify it.
Other answers are good, but you can expand this to easily handle more variables:
$variables = array($a, $b, $c, $d, ....);
$howManyNulls = 0;
foreach($variables as $v){
if($v == ''){
$howManyNulls++;
}
}
if($howManyNulls == count($variables) - 2){
// do stuff
}
you can try this
if($a!="" && $b!="" && $c!="")
{
** do the things here **
}
else if(($a!="" && $b!="") || ($b!="" && $c!="") || ($a!="" && $c!=""))
{
**do another things here**
}
Try:
if($a!="" && $b!="" && $c!=""){
** do the things here **
}else if(($a!="" && $b!="") || ($a!="" && $c!="") || ($b!="" && $c!="")){
**do another things here**
}
$var[] = empty($a) ? 0:$a;
$var[] = empty($b) ? 0:$b;
$var[] = empty($c) ? 0:$c;
$varm = array_count_values($var);
if ($varm[0] === 0) {
//Code for when all aren't empty!
} elseif ($varm[0] === 1) {
//Code for when two aren't empty!
}
N.B; You may need to replace the 0 for a string/integer that will never crop up, if your variables are always strings or empty then 0 will do for this. The method for using bools within this would require more code.
$nullCount = 0
if($a!=""){ ++$nullCount; }
if($b!=""){ ++$nullCount; }
if($c!=""){ ++$nullCount; }
if($nullCount == 3){ // all are null
// do smth
}else if($nullCount == 2){ // only two are null
// do other
}
Just for fun, here's something potentially maintainable, should the list of arguments increase:
function countGoodValues(...$values) {
$count = 0;
foreach($values as $value) {
if($value != "") {
++$count;
}
}
return $count;
}
$goodValues = countGoodValues($a, $b, $c); // Or more... or less
if($goodValues == 3) {
// Do something here
}
else if($goodValues == 2) {
// And something else
}
Reference for the ... construct (examples #7 and #8 in particular) are available on php.net.
You can use double typecasting (to boolean, then to number) in conjunction with summing:
$count = (bool)$a + (bool)$b + (bool)$c;
if ($count == 3)
// ** do the things here **
else if ($count == 2)
//**do another things here**
There is also possible such solution:
<?php
$a= 'd';
$b = 'a';
$c = '';
$arr = array( (int) ($a!=""), (int) ($b!=""), (int) ($c!=""));
$occ = array_count_values($arr);
if ($occ[1] == 3) {
echo "first";
}
else if($occ[1] == 2) {
echo "second";
}
If you have 3 variables as in your example you can probably use simple comparisons, but if you have 4 or more variables you would get too big condition that couldn't be read.
if (($a!="") + ($b!="") + ($c!="") == 2) {
// two of the variables are not empty
}
The expression a!="" should return true (which is 1 as an integer) when the string is not empty. When you sum whether each of the strings meets this condition, you get the number of non-empty strings.
if (count(array_filter([$a, $b, $c])) >= 2) ...
This is true if at least two of the variables are truthy. That means $var == true is true, which may be slightly different than $var != "". If you require != "", write it as test:
if (count(array_filter([$a, $b, $c], function ($var) { return $var != ""; })) >= 2) ...
if($a!="" && $b!="" && $c!="") {
echo "All notnull";
} elseif(($a!="" && $b!="") || ($b!="" && $c!="") || ($a!="" && $c!="")) {
echo "Either 2 notnull";
}
I have simple code which is something like this:
$options = new Options();
$page = new Pages();
if($page->page_limit() <= $options->pageno) {
$page->userid = $user_details->userid;
$page->date_of_pub = $_POST['date_of_pub'];
$resultss=$page->page_create();
}
else {
$resultss=false;
}
Then at bottom I am putting a condition
if(isset($resultss) && isset($resultss) == true) {
echo $alert->SuccessMsg("Page created successfully!");
}
if(isset($resultss) && isset($resultss) == false) {
echo $alert->ErrorMsg("You Have Been Reached to your maximum page limit");
}
Instead of printing error value even I have set the value of $result = false is shows success message, means its showing $resultss = true statement.
Suggest something. This is so strange. I got the answer thank you so much :)
One more thing.
can you please tell me how can I get rid of this " echo $alert->ErrorMsg" this is so annoying for all the class and functions. I want to make it a single word.
You check the same twice:
isset($resultss) && isset($resultss)==true
You should do:
isset($ressults) && $ressults == true
You have a problem in your logic with isset(). This:
if(isset($resultss) && isset($resultss)==true){echo $alert->SuccessMsg("Page created successfully!");}
if(isset($resultss) && isset($resultss)==false){echo $alert->ErrorMsg("You Have Been Reached to your maximum page limit");}
Should be
if(isset($resultss) && $resultss == true){echo $alert->SuccessMsg("Page created successfully!");}
if(isset($resultss) && $resultss ===false){echo $alert->ErrorMsg("You Have Been Reached to your maximum page limit");}
In your existing code, the second isset() in each statement is incorrect. In the first one, it is redundant, and you are asking the same thing as if(isset($resultss) && isset($resultss)), which is always true. In the second one, isset($resultss) && isset($resultss)==false could never be true. It's like true && false.
You really don't need to check if the variables are set, since you are setting it in both branches of the if/else. Just do:
if ($resultss) {
echo $alert->SuccessMsg("Page created successfully!");
} else {
echo $alert->ErrorMsg("You Have Been Reached to your maximum page limit");
}
Change your IF conditions to:
if(isset($resultss) && $resultss == true)
isset(x) and isset(x) == true bacially mean the same. What you want is to match two conditions:
the variable IS SET and IT IS EQUAL TO TRUE.
Since I'm not sure what the value might be I'd suggest using these confitions:
if(isset($resultss) && $resultss !== false) //the value is set and it is NOT set to false
AND
if(isset($resultss) && $resultss === false) //the value is set to false
Have you tried setting it to false as default?
$options = new Options();
$page = new Pages();
$resultss = false;
if($page->page_limit() <= $options->pageno){
$page->userid = $user_details->userid;
$page->date_of_pub = $_POST['date_of_pub'];
$resultss = $page->page_create();
}
What's wrong with this? It's not working out
// define
$prv=0;
if(isset($_GET['prv'])) {
$prv = intval($_GET['prv']);
}
// security
if($prv != 0 OR $prv != 2) {
die("<p>Error</p>");
}
This always goes through the die() part, even when prv is undefined or is defined as 2 in the url (and is 2)
And this does works:
// security
if($prv == 0 OR $prv == 2) { } else {
die("<p>Error</p>");
}
Change your if statement to:
// security
if($prv != 0 AND $prv != 2) {
die("<p>Error</p>");
}
With the OR it will always evaluate as true because when $prv == 0 it does not equal 2. Makes sense?
Whatever the value of "prv" is, it certainly cannot be both 0 and 2 at the same time, so one of the conditions is always true; that's why you get in that clause.
Break it down:
if $prv is not 0, the first condition passes and the OR succeeds
otherwise, $pev must be 0. Therefore it must be "not 2", so the OR succeeds.
Try && instead.
== replace !=
if($prv != 0 AND $prv != 2) {
die("<p>Error</p>");
}
What I'm doing is, if I haven't got an ID in either $_POST or $_SESSION then redirecting. Preference is given to $_POST. So I have this:
$bool = 0;
if (isset($_POST['id'])) {
$bool = 1;
} elseif (isset($_SESSION['id'])) {
$bool = 1;
}
if (!$bool) {
...//redirect
}
Is there a quicker way to write this, APART from just removing the braces?
if(!( isset($_POST['id']) || isset($_SESSION['id']) ))
redirect();
(not sure if I understand how what's given to $_POST is preference).
You could just do:
$has_id = isset($_POST['id']) || isset($_SESSION['id']);
if (!$has_id) {
// redirect
}
(I'd recommend you to give your variables more descriptive names than just $bool.)
Although if you aren't using the variable for anything else, you could just do:
if (!isset($_POST['id']) && !isset($_SESSION['id'])) {
// redirect
}
if (isset($_POST['id']) || isset($_SESSION['id'])) {
$bool = 1;
}
This will do it, simples
$bool = (isset($_POST['id']) || isset($_SESSION['id'])) ? 1 : 0; // if isset, 1
($bool == 1?header(Location: www.whatever.com):null;
Using Conditional Operator, you can achieve this in one line statement
Example:
c = (a == b) ? d : e;