When I am displaying my array by using var_dump I get the following result:
array(1) { [0]=> NULL }
I want to apply a condition that when my array has a null value it should do something. I have tried using array[0]== NULL and array[0]= NULL inside my condition but it does not work. Can anyone tell me what could be the correct condition for it?
PHPs empty() checks if a variable doesn't exist or has a falsey value (like array(), 0, null, false, etc).
<?php
if (!empty($array[0])) {
echo "Not empty";
} else {
echo "empty";
}
?>
or by using is_null
<?php
if(is_null($array[0])) {
echo "empty";
} else {
echo "not empty";
}
?>
or
<?php
if($array[0] === NULL) {
echo "empty";
} else {
echo "not empty";
}
?>
You can do it by several ways:
if(is_null($array[0])) {}
or
if(!isset($array[0])) {}
or
if($array[0] === null) {}
By the way, == makes a comparison, = is an assignment (even in an if statement) and === compares values and type.
$arr = array();
if (!empty($arr)){
//do your code
}
else {
echo "Hey I'm empty";
}
Related
I am checking if two values are null. If both are null I want to return false, if either or both are not null, I want to return true.
My current code returns true only when both are not null but I want it to return true when either or not null.
// check if both null
if (!isset($myarray['dataone'], $myarray['datatwo']))
{
echo 'false';
);
} else {
echo 'true';
);
}
return $emptytabs;
For that you can use relational operators. AND (&&) OR (||)
By using AND (&&) operators.
if ( (!isset($myarray['dataone']) || (!isset$myarray['datatwo'] ))
{
echo 'false';
}
else
{
echo 'true';
}
By using OR ( || ) operators.
if (isset($myarray['dataone'] && isset$myarray['datatwo'])
{
echo 'false';
}
else
{
echo 'true';
}
// check if both null
if ( !isset($myarray['dataone']) && !isset($myarray['datatwo'])) {
echo 'false';
} else {
echo 'true';
}
// check if one or both are null
if ( !isset($myarray['dataone']) || !isset($myarray['datatwo'])) {
echo 'false';
} else {
echo 'true';
}
// check if both null
if ( !isset($myarray['dataone'], $myarray['datatwo']) )
{
echo 'false';
} else {
echo 'true';
}
return $emptytabs;
this approach you provided is totally true , but it only return true if all the provided parameters are set according to php documentations .
so your code should works correctly . except you have unwanted parentheses that should deleted
The simplest way is to use the OR (||) operator. You want to show 'true' if one thing is set OR another thing is set. Just say that with code.
if ( isset($myarray['dataone']) || isset($myarray['datatwo']) ) {
echo 'true';
} else {
echo 'false';
}
Using the AND operator adds pointless complexity by checking that both of the two things are not set in order for it to show 'false'. That's not an intuitive way to think about it, so it doesn't make sense to write the code that way.
DISCLAIMER: This answer is opinionated.
i need to use if statement inside my table
the value of the row is "Released" but i want to show Pending on my html table. how can i achieve it. this is my current code. what's wrong with my if statement?
if (strlen($row['signed']) == "Released") {
echo "Pending";
}
else{
echo $row['signed'];
}
strlen checks for string length. first check either signed is set in the array and then check if value is equal
if (isset($row['signed']) && $row['signed'] == "Released") {
echo "Pending";
}
else{
echo $row['signed'];
}
strlen() returns the length of the argument, so it returns an integer. You can check if value is equals to the string which you want something like this:
if ($row['signed'] == "Released") {
echo "Pending";
} else {
echo "Released";
}
strlen() is used to count the length of the string, to check if it matches "Released", just use == to compare:
if ($row['signed'] == "Released") {
echo "Pending";
} else {
echo $row['signed'];
}
To find out is $row['signed'] is set, just use isset():
if (isset($row['signed'])) {
echo "Pending";
} else {
echo $row['signed'];
}
More information on isset(): http://php.net/manual/en/function.isset.php
More information on PHP operators: http://php.net/manual/en/language.operators.php
Try this:
if ($row['signed'] == "Released") {
$value = "Pending";
} else {
$value = "Released"
}
And add <?php echo $value; ?> in your table
Following is my code here actually o/p should be hi..but it is giving no
<?php
$arr=array('Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday');
$c='xyz,ccc';
if(in_array(isset($c) && $c,$arr))
{
echo 'hi';
}
else
{
echo 'no';
}
?>
output:hi
actual result should be 'no'.
Side note, this is bad code:
in_array(isset($weekendArr) && $weekendArr,$arr)
do it like
isset($weekendArr) && in_array($weekendArr,$arr)
and in_array is not strict so this
in_array(true,array('w','s'))
will be allways TRUE
do it with:
in_array(true,array('w','s'),true)
and you see.
And you can't check an array with an array the $needle be an STRING here.
The only solution is to do splitt your STRING into two values and then check two times for TRUE
$c='Sunday,Monday';
foreach(explode(',',$c) as $check){
if(in_array($c,$arr,true))
{
echo $check.' is in array';
}
else
{
echo $check.' is NOT in array';
}
}
Hope that helps a little.
<?php
$listDays=array('Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday');
$day='Sunday'; //You cant test both days ! Just one value at a time
if(true === in_array($day, $listDays))
{
echo 'hi';
}
else
{
echo 'no';
}
?>
Or option two if you want to test different days
<?php
$listDays=array('Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday');
$dayToTest='Sunday, Monday'; //Here we have multiple days
$tabTest = preg_split(',', $day); //split into an array
//Then test for each string in tabTest
foreach($tabTest as $string)
{
if(true === in_array($string, $listDays))
{
echo $string.' is OK';
}
else
{
echo 'no';
}
}
?>
Change your code to:
<?php
$arr=array('Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday');
$c='Sunday,Monday';
if(in_array(isset($c) && $c,$arr))
{
echo 'hi';
}
else
{
echo 'no';
}
I wrote this:
$a[] = "guy";
$b[] = "g";
function login($a1, $b1)
{
if( user($a1) == true and pass1($b1) == true)
{
login2($a1, $b1);
}
else
{
echo "error!!!!";
}
}
function login2($a1, $b1)
{
if (array_search($_REQUEST["user"],$a1) == array_search($_REQUEST["pass"],$b1))
{
echo "you are logged in";
}
else
{
echo "erorr";
}
}
function user($user1)
{
if(in_array($_REQUEST["user"],$user1))
{
echo "gooooooood?";
}
}
function pass1($pas)
{
if(in_array($_REQUEST["pass"],$pas))
{
echo "goooooooood!!!!!!!!";
}
else
{
echo "bad";
}
}
login($a, $b);
and I know that pass() and user() are true because I changed their positions on the function login() and every time I did this the first argument was returned as true and it didn't check the second one. Does anyone know why this happens?
user and pass1 functions should return true or false, not echo out.
Your user and pass1 functions are not returning an explicit value, so they are implicitly returning the NULL value. As described on this page in the PHP manual the NULL type is converted to false when a boolean is expected. So both your user and pass1 functions return false every time.
The && and and logical operators in PHP use short-circuiting for efficiency (see the first code example on this page of the PHP manual) so in any and statement whose first operand evaluates to false it can never be possible for the whole and statement to evaluate to true, so the second operand (in the case of your code above, the second operand is the call to pass1($b1)) is never evaluated because it would be a waste of time to do so.
Which means you're seeing the user function being called, but never the pass1 function.
Try using this instead:
$a[] = "guy";
$b[] = "g";
function login($a1, $b1)
{
if( user($a1) == true && pass1($b1) == true)
login2($a1, $b1);
else
echo "error!!!!";
}
function login2($a1, $b1)
{
if (array_search($_REQUEST["user"],$a1) == array_search($_REQUEST["pass"],$b1))
echo "you are logged in";
else
echo "erorr";
}
function user($user1)
{
if(in_array($_REQUEST["user"],$user1))
echo "gooooooood?";
}
function pass1($pas)
{
if(in_array($_REQUEST["pass"],$pas))
echo"goooooooood!!!!!!!!";
else
echo "bad";
}
login($a, $b);
in if condition i want to check
if(isset($_GET['q']))
{
echo "ok";
}
esle
{
echo "not ok";
}
when $_GET['q']=0 if send me in else part.
But i want to go in if .
if $_GET['q'] have any value even for 0 if should print ok
any help pls ?
This is what isset does. Try:
$x["q"] = 0;
var_dump(isset($x["q"]));
You will get true. If you think isset() returns false on 0 you are looking at the wrong place, look for a bug elsewhere.
0 is not null http://php.net/manual/en/function.isset.php
You might need something like this considering the value you want is integer
if(isset($_GET['q']) && intval($_GET['q']) > 0 )
{
echo "ok";
}
else
{
echo "not ok";
}
perhaps array_key_exists() would be more appropriate.
if ( array_key_exists( 'q', $_GET ) ) ...
I think this is the correct one...
if(array_key_exists('q', $_GET)){
echo "ok";
}
else{
echo "not ok";
}