I am getting this PHP error, what does it mean?
Notice: Undefined offset: 0 in
C:xampphtdocsmywebsitereddit_vote_tutsrcvotes.php on line 41
From this code:
<?php
include("config.php");
function getAllVotes($id)
{
$votes = array();
$q = "SELECT * FROM entries WHERE id = $id";
$r = mysql_query($q);
if(mysql_num_rows($r)==1)//id found in the table
{
$row = mysql_fetch_assoc($r);
$votes[0] = $row['votes_up'];
$votes[1] = $row['votes_down'];
}
return $votes;
}
function getEffectiveVotes($id)
{
$votes = getAllVotes($id);
$effectiveVote = $votes[0] - $votes[1]; //ERROR THROWN HERE
return $effectiveVote;
}
$id = $_POST['id'];
$action = $_POST['action'];
//get the current votes
$cur_votes = getAllVotes($id);
//ok, now update the votes
if($action=='vote_up') //voting up
{
$votes_up = $cur_votes[0]+1; //AND ERROR THROWN HERE
$q = "UPDATE threads SET votes_up = $votes_up WHERE id = $id";
}
elseif($action=='vote_down')
{
$votes_down = $cur_votes[1]+1;
$q = "UPDATE threads SET votes_down = $votes_down WHERE id = $id";
}
$r = mysql_query($q);
if($r)
{
$effectiveVote = getEffectiveVotes($id);
echo $effectiveVote." votes";
}
elseif(!$r) //voting failed
{
echo "Failed!";
}
?>
asked Jul 1, 2011 at 14:51
4
You are asking for the value at key 0 of $votes. It is an array that does not contain that key.
The array $votes is not set, so when PHP is trying to access the key 0 of the array, it encounters an undefined offset for [0] and [1] and throws the error.
If you have an array:
$votes = array('1','2','3');
We can now access:
$votes[0];
$votes[1];
$votes[2];
If we try and access:
$votes[3];
We will get the error «Notice: Undefined offset: 3»
toddmo
19.8k13 gold badges91 silver badges102 bronze badges
answered Jul 1, 2011 at 14:55
YonoRanYonoRan
1,6989 silver badges7 bronze badges
6
first, check that the array actually exists, you could try something like
if (isset($votes)) {
// Do bad things to the votes array
}
answered Mar 24, 2014 at 8:36
This answer helped me https://stackoverflow.com/a/18880670/1821607
The reason of crush — index 0 wasn’t set. Simple $array = $array + array(null) did the trick. Or you should check whether array element on index 0 is set via isset($array[0]). The second variant is the best approach for me.
answered Dec 1, 2015 at 10:17
Use print_r($votes); to inspect the array $votes, you will see that key 0 does not exist there. It will return NULL and throw that error.
answered Jul 23, 2011 at 9:59
0
getAllVotes() isn’t returning an array with the indexes 0 or 1. Make sure it’s returning the data you want by calling var_dump() on the result.
answered Jul 1, 2011 at 14:54
Tim CooperTim Cooper
156k38 gold badges327 silver badges277 bronze badges
I encountered this as well and the solution is simple, dont hardcode the array index position in your code.
Instead of
$data[0]['somekey'] do
foreach($data as $data_item)
{
echo $data_item['somekey'];
}
If there is an array or more you can perform your desired action inside the loop, but if it’s undefined it will not bring an error. you can also add other checks on top of that.
You could also add a variable and increment it in a for in loop to limit your looping if you want only the first positions or something.
answered Jul 29, 2018 at 12:50
MihaiMihai
821 silver badge6 bronze badges
As explained it happens because there is no data in the $cur_votes[0] and hence it throws an error.
To ensure your code works fine, before performing "$votes_up = $cur_votes[0]+1;" echo the $cur_votes[0] value to see if there is any value stored or not.
Surely, there is no value stored.
answered Mar 27, 2013 at 9:00
EspantaEspanta
1,0501 gold badge17 silver badges27 bronze badges
function getEffectiveVotes($id)
According to the function header, there is only one parameter variable ($id).
Thus, on line 27, the votes[] array is undefined and out of scope. You need to add another
parameter value to the function header so that function getEffectiveVotes() knows to expect two parameters. I’m rusty, but something like this would work.
function getEffectiveVotes($id, $votes)
I’m not saying this is how it should be done, but you might want to research how PHP
passes its arrays and decide if you need to explicitly state to pass it by reference
function getEffectiveVotes($id &$votes) <---I forget, no time to look it up right now.
Lastly, call function getEffectiveVotes() with both arguments wherever it is supposed to be called.
Cheers.
answered Jun 21, 2013 at 3:46
Anthony RutledgeAnthony Rutledge
6,5321 gold badge36 silver badges44 bronze badges
As you might have already about knew the error. This is due to trying to access the empty array or trying to access the value of empty key of array. In my project, I am dealing with this error with counting the array and displaying result.
You can do it like this:
if(count($votes) == '0'){
echo 'Sorry, no votes are available at the moment.';
}
else{
//do the stuff with votes
}
count($votes) counts the $votes array. If it is equal to zero (0), you can display your custom message or redirect to certain page else you can do stuff with $votes. In this way you can remove the Notice: Undefined offset: 0 in notice in PHP.
answered Feb 19, 2016 at 5:33
VijayRanaVijayRana
9131 gold badge12 silver badges35 bronze badges
If you leave out the brackets then PHP will assign the keys by default.
Try this:
$votes = $row['votes_up'];
$votes = $row['votes_down'];
answered Sep 22, 2014 at 19:07
DavidDavid
4292 gold badges5 silver badges14 bronze badges
In my case it was a simple type
$_SESSION['role' == 'ge']
I was missing the correct closing bracket
$_SESSION['role'] == 'ge'
answered Nov 23, 2018 at 7:44
Hammad KhanHammad Khan
16k16 gold badges111 silver badges134 bronze badges
If you are using dompdf/dompdf and error occure in vendor/dompdf/dompdf/src/Cellmap.php then
It looks like we’re using the wrong frame id in the update_row_group method. Initial testing seems to confirm this. Though that may be because this is strictly a paged table issue and not too many of the documents in my test bed have paged tables.
Can you try changing line 800 to:
$r_rows = $this->_frames[$g_key][«rows»];
($g_key instead of $r_key)
https://github.com/dompdf/dompdf/issues/1295
answered Dec 19, 2018 at 7:51
Use mysql row instead
mysql_fetch_row($r)
Meanwhile consider using mysqli or PDO
?>
Try seeding data with command: php artisan db:seed.
sssurii
7284 silver badges15 bronze badges
answered Jul 26, 2021 at 4:09
Nam SamaNam Sama
3253 silver badges5 bronze badges
0
its just a warning use:
error_reporting(0);
it shows when we do not initialize array and direct assigning value to indexes.
somefunction{
$raja[0]="this";
$raja[1]="that";
}
instead :
somefunction{
$raja=array(0=>'this',1='that');
//or
$raja=array("this","that");
}
it just notification, do not generate any output error or any unexpected output.
answered Aug 27, 2014 at 7:59
3
I am getting this PHP error, what does it mean?
Notice: Undefined offset: 0 in
C:xampphtdocsmywebsitereddit_vote_tutsrcvotes.php on line 41
From this code:
<?php
include("config.php");
function getAllVotes($id)
{
$votes = array();
$q = "SELECT * FROM entries WHERE id = $id";
$r = mysql_query($q);
if(mysql_num_rows($r)==1)//id found in the table
{
$row = mysql_fetch_assoc($r);
$votes[0] = $row['votes_up'];
$votes[1] = $row['votes_down'];
}
return $votes;
}
function getEffectiveVotes($id)
{
$votes = getAllVotes($id);
$effectiveVote = $votes[0] - $votes[1]; //ERROR THROWN HERE
return $effectiveVote;
}
$id = $_POST['id'];
$action = $_POST['action'];
//get the current votes
$cur_votes = getAllVotes($id);
//ok, now update the votes
if($action=='vote_up') //voting up
{
$votes_up = $cur_votes[0]+1; //AND ERROR THROWN HERE
$q = "UPDATE threads SET votes_up = $votes_up WHERE id = $id";
}
elseif($action=='vote_down')
{
$votes_down = $cur_votes[1]+1;
$q = "UPDATE threads SET votes_down = $votes_down WHERE id = $id";
}
$r = mysql_query($q);
if($r)
{
$effectiveVote = getEffectiveVotes($id);
echo $effectiveVote." votes";
}
elseif(!$r) //voting failed
{
echo "Failed!";
}
?>
asked Jul 1, 2011 at 14:51
4
You are asking for the value at key 0 of $votes. It is an array that does not contain that key.
The array $votes is not set, so when PHP is trying to access the key 0 of the array, it encounters an undefined offset for [0] and [1] and throws the error.
If you have an array:
$votes = array('1','2','3');
We can now access:
$votes[0];
$votes[1];
$votes[2];
If we try and access:
$votes[3];
We will get the error «Notice: Undefined offset: 3»
toddmo
19.8k13 gold badges91 silver badges102 bronze badges
answered Jul 1, 2011 at 14:55
YonoRanYonoRan
1,6989 silver badges7 bronze badges
6
first, check that the array actually exists, you could try something like
if (isset($votes)) {
// Do bad things to the votes array
}
answered Mar 24, 2014 at 8:36
This answer helped me https://stackoverflow.com/a/18880670/1821607
The reason of crush — index 0 wasn’t set. Simple $array = $array + array(null) did the trick. Or you should check whether array element on index 0 is set via isset($array[0]). The second variant is the best approach for me.
answered Dec 1, 2015 at 10:17
Use print_r($votes); to inspect the array $votes, you will see that key 0 does not exist there. It will return NULL and throw that error.
answered Jul 23, 2011 at 9:59
0
getAllVotes() isn’t returning an array with the indexes 0 or 1. Make sure it’s returning the data you want by calling var_dump() on the result.
answered Jul 1, 2011 at 14:54
Tim CooperTim Cooper
156k38 gold badges327 silver badges277 bronze badges
I encountered this as well and the solution is simple, dont hardcode the array index position in your code.
Instead of
$data[0]['somekey'] do
foreach($data as $data_item)
{
echo $data_item['somekey'];
}
If there is an array or more you can perform your desired action inside the loop, but if it’s undefined it will not bring an error. you can also add other checks on top of that.
You could also add a variable and increment it in a for in loop to limit your looping if you want only the first positions or something.
answered Jul 29, 2018 at 12:50
MihaiMihai
821 silver badge6 bronze badges
As explained it happens because there is no data in the $cur_votes[0] and hence it throws an error.
To ensure your code works fine, before performing "$votes_up = $cur_votes[0]+1;" echo the $cur_votes[0] value to see if there is any value stored or not.
Surely, there is no value stored.
answered Mar 27, 2013 at 9:00
EspantaEspanta
1,0501 gold badge17 silver badges27 bronze badges
function getEffectiveVotes($id)
According to the function header, there is only one parameter variable ($id).
Thus, on line 27, the votes[] array is undefined and out of scope. You need to add another
parameter value to the function header so that function getEffectiveVotes() knows to expect two parameters. I’m rusty, but something like this would work.
function getEffectiveVotes($id, $votes)
I’m not saying this is how it should be done, but you might want to research how PHP
passes its arrays and decide if you need to explicitly state to pass it by reference
function getEffectiveVotes($id &$votes) <---I forget, no time to look it up right now.
Lastly, call function getEffectiveVotes() with both arguments wherever it is supposed to be called.
Cheers.
answered Jun 21, 2013 at 3:46
Anthony RutledgeAnthony Rutledge
6,5321 gold badge36 silver badges44 bronze badges
As you might have already about knew the error. This is due to trying to access the empty array or trying to access the value of empty key of array. In my project, I am dealing with this error with counting the array and displaying result.
You can do it like this:
if(count($votes) == '0'){
echo 'Sorry, no votes are available at the moment.';
}
else{
//do the stuff with votes
}
count($votes) counts the $votes array. If it is equal to zero (0), you can display your custom message or redirect to certain page else you can do stuff with $votes. In this way you can remove the Notice: Undefined offset: 0 in notice in PHP.
answered Feb 19, 2016 at 5:33
VijayRanaVijayRana
9131 gold badge12 silver badges35 bronze badges
If you leave out the brackets then PHP will assign the keys by default.
Try this:
$votes = $row['votes_up'];
$votes = $row['votes_down'];
answered Sep 22, 2014 at 19:07
DavidDavid
4292 gold badges5 silver badges14 bronze badges
In my case it was a simple type
$_SESSION['role' == 'ge']
I was missing the correct closing bracket
$_SESSION['role'] == 'ge'
answered Nov 23, 2018 at 7:44
Hammad KhanHammad Khan
16k16 gold badges111 silver badges134 bronze badges
If you are using dompdf/dompdf and error occure in vendor/dompdf/dompdf/src/Cellmap.php then
It looks like we’re using the wrong frame id in the update_row_group method. Initial testing seems to confirm this. Though that may be because this is strictly a paged table issue and not too many of the documents in my test bed have paged tables.
Can you try changing line 800 to:
$r_rows = $this->_frames[$g_key][«rows»];
($g_key instead of $r_key)
https://github.com/dompdf/dompdf/issues/1295
answered Dec 19, 2018 at 7:51
Use mysql row instead
mysql_fetch_row($r)
Meanwhile consider using mysqli or PDO
?>
Try seeding data with command: php artisan db:seed.
sssurii
7284 silver badges15 bronze badges
answered Jul 26, 2021 at 4:09
Nam SamaNam Sama
3253 silver badges5 bronze badges
0
its just a warning use:
error_reporting(0);
it shows when we do not initialize array and direct assigning value to indexes.
somefunction{
$raja[0]="this";
$raja[1]="that";
}
instead :
somefunction{
$raja=array(0=>'this',1='that');
//or
$raja=array("this","that");
}
it just notification, do not generate any output error or any unexpected output.
answered Aug 27, 2014 at 7:59
3
I am getting this PHP error, what does it mean?
Notice: Undefined offset: 0 in
C:xampphtdocsmywebsitereddit_vote_tutsrcvotes.php on line 41
From this code:
<?php
include("config.php");
function getAllVotes($id)
{
$votes = array();
$q = "SELECT * FROM entries WHERE id = $id";
$r = mysql_query($q);
if(mysql_num_rows($r)==1)//id found in the table
{
$row = mysql_fetch_assoc($r);
$votes[0] = $row['votes_up'];
$votes[1] = $row['votes_down'];
}
return $votes;
}
function getEffectiveVotes($id)
{
$votes = getAllVotes($id);
$effectiveVote = $votes[0] - $votes[1]; //ERROR THROWN HERE
return $effectiveVote;
}
$id = $_POST['id'];
$action = $_POST['action'];
//get the current votes
$cur_votes = getAllVotes($id);
//ok, now update the votes
if($action=='vote_up') //voting up
{
$votes_up = $cur_votes[0]+1; //AND ERROR THROWN HERE
$q = "UPDATE threads SET votes_up = $votes_up WHERE id = $id";
}
elseif($action=='vote_down')
{
$votes_down = $cur_votes[1]+1;
$q = "UPDATE threads SET votes_down = $votes_down WHERE id = $id";
}
$r = mysql_query($q);
if($r)
{
$effectiveVote = getEffectiveVotes($id);
echo $effectiveVote." votes";
}
elseif(!$r) //voting failed
{
echo "Failed!";
}
?>
asked Jul 1, 2011 at 14:51
4
You are asking for the value at key 0 of $votes. It is an array that does not contain that key.
The array $votes is not set, so when PHP is trying to access the key 0 of the array, it encounters an undefined offset for [0] and [1] and throws the error.
If you have an array:
$votes = array('1','2','3');
We can now access:
$votes[0];
$votes[1];
$votes[2];
If we try and access:
$votes[3];
We will get the error «Notice: Undefined offset: 3»
toddmo
19.8k13 gold badges91 silver badges102 bronze badges
answered Jul 1, 2011 at 14:55
YonoRanYonoRan
1,6989 silver badges7 bronze badges
6
first, check that the array actually exists, you could try something like
if (isset($votes)) {
// Do bad things to the votes array
}
answered Mar 24, 2014 at 8:36
This answer helped me https://stackoverflow.com/a/18880670/1821607
The reason of crush — index 0 wasn’t set. Simple $array = $array + array(null) did the trick. Or you should check whether array element on index 0 is set via isset($array[0]). The second variant is the best approach for me.
answered Dec 1, 2015 at 10:17
Use print_r($votes); to inspect the array $votes, you will see that key 0 does not exist there. It will return NULL and throw that error.
answered Jul 23, 2011 at 9:59
0
getAllVotes() isn’t returning an array with the indexes 0 or 1. Make sure it’s returning the data you want by calling var_dump() on the result.
answered Jul 1, 2011 at 14:54
Tim CooperTim Cooper
156k38 gold badges327 silver badges277 bronze badges
I encountered this as well and the solution is simple, dont hardcode the array index position in your code.
Instead of
$data[0]['somekey'] do
foreach($data as $data_item)
{
echo $data_item['somekey'];
}
If there is an array or more you can perform your desired action inside the loop, but if it’s undefined it will not bring an error. you can also add other checks on top of that.
You could also add a variable and increment it in a for in loop to limit your looping if you want only the first positions or something.
answered Jul 29, 2018 at 12:50
MihaiMihai
821 silver badge6 bronze badges
As explained it happens because there is no data in the $cur_votes[0] and hence it throws an error.
To ensure your code works fine, before performing "$votes_up = $cur_votes[0]+1;" echo the $cur_votes[0] value to see if there is any value stored or not.
Surely, there is no value stored.
answered Mar 27, 2013 at 9:00
EspantaEspanta
1,0501 gold badge17 silver badges27 bronze badges
function getEffectiveVotes($id)
According to the function header, there is only one parameter variable ($id).
Thus, on line 27, the votes[] array is undefined and out of scope. You need to add another
parameter value to the function header so that function getEffectiveVotes() knows to expect two parameters. I’m rusty, but something like this would work.
function getEffectiveVotes($id, $votes)
I’m not saying this is how it should be done, but you might want to research how PHP
passes its arrays and decide if you need to explicitly state to pass it by reference
function getEffectiveVotes($id &$votes) <---I forget, no time to look it up right now.
Lastly, call function getEffectiveVotes() with both arguments wherever it is supposed to be called.
Cheers.
answered Jun 21, 2013 at 3:46
Anthony RutledgeAnthony Rutledge
6,5321 gold badge36 silver badges44 bronze badges
As you might have already about knew the error. This is due to trying to access the empty array or trying to access the value of empty key of array. In my project, I am dealing with this error with counting the array and displaying result.
You can do it like this:
if(count($votes) == '0'){
echo 'Sorry, no votes are available at the moment.';
}
else{
//do the stuff with votes
}
count($votes) counts the $votes array. If it is equal to zero (0), you can display your custom message or redirect to certain page else you can do stuff with $votes. In this way you can remove the Notice: Undefined offset: 0 in notice in PHP.
answered Feb 19, 2016 at 5:33
VijayRanaVijayRana
9131 gold badge12 silver badges35 bronze badges
If you leave out the brackets then PHP will assign the keys by default.
Try this:
$votes = $row['votes_up'];
$votes = $row['votes_down'];
answered Sep 22, 2014 at 19:07
DavidDavid
4292 gold badges5 silver badges14 bronze badges
In my case it was a simple type
$_SESSION['role' == 'ge']
I was missing the correct closing bracket
$_SESSION['role'] == 'ge'
answered Nov 23, 2018 at 7:44
Hammad KhanHammad Khan
16k16 gold badges111 silver badges134 bronze badges
If you are using dompdf/dompdf and error occure in vendor/dompdf/dompdf/src/Cellmap.php then
It looks like we’re using the wrong frame id in the update_row_group method. Initial testing seems to confirm this. Though that may be because this is strictly a paged table issue and not too many of the documents in my test bed have paged tables.
Can you try changing line 800 to:
$r_rows = $this->_frames[$g_key][«rows»];
($g_key instead of $r_key)
https://github.com/dompdf/dompdf/issues/1295
answered Dec 19, 2018 at 7:51
Use mysql row instead
mysql_fetch_row($r)
Meanwhile consider using mysqli or PDO
?>
Try seeding data with command: php artisan db:seed.
sssurii
7284 silver badges15 bronze badges
answered Jul 26, 2021 at 4:09
Nam SamaNam Sama
3253 silver badges5 bronze badges
0
its just a warning use:
error_reporting(0);
it shows when we do not initialize array and direct assigning value to indexes.
somefunction{
$raja[0]="this";
$raja[1]="that";
}
instead :
somefunction{
$raja=array(0=>'this',1='that');
//or
$raja=array("this","that");
}
it just notification, do not generate any output error or any unexpected output.
answered Aug 27, 2014 at 7:59
3
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Save Article
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Save Article
The Offset that does not exist in an array then it is called as an undefined offset. Undefined offset error is similar to ArrayOutOfBoundException in Java. If we access an index that does not exist or an empty offset, it will lead to an undefined offset error.
Example: Following PHP code explains how we can access array elements. If the accessed index is not present then it gives an undefined offset error.
php
<?php
$students = array(
0 => 'Rohan',
1 => 'Arjun',
2 => 'Niharika'
);
echo $students[0];
echo $students[5];
echo $students[key];
?>
Output:
There are some methods to avoid undefined offset error that are discussed below:
- isset() function: This function checks whether the variable is set and is not equal to null. It also checks if array or array key has null value or not.
Example:
php
<?php
$students = array(
0 => 'Rohan',
1 => 'Arjun',
2 => 'Niharika'
);
if(isset($students[5])) {
echo $students[5];
}
else {
echo "Index not present";
}
?>
Output:
Index not present
- empty() function: This function checks whether the variable or index value in an array is empty or not.
php
<?php
$students = array(
0 => 'Rohan',
1 => 'Arjun',
2 => 'Niharika'
);
if(!empty($students[5])) {
echo $students[5];
}
else {
echo "Index not present";
}
?>
Output:
Index not present
Example:
php
<?php
function Exists($index, $array) {
if (array_key_exists($index, $array)) {
echo "Key Found";
}
else{
echo "Key not Found";
}
}
$array = array(
"ram" => 25,
"krishna" => 10,
"aakash" => 20
);
$index = "aakash";
print_r(Exists($index, $array));
?>
Output:
Key Found
PHP is a server-side scripting language designed specifically for web development. You can learn PHP from the ground up by following this PHP Tutorial and PHP Examples.
Before discovering how to avoid the PHP undefined offset error, let’s see what it is. The undefined offset is the one that doesn’t exist inside an array. An attempt to access such an index will lead to an error, which is known as undefined offset error.
Let’s see an example:
<?php
// Declare and initialize an array
// $students = ['Ann', 'Jennifer', 'Mary']
$students = [
0 => 'Ann',
1 => 'Jennifer',
2 => 'Mary',
];
// Leyla
echo $students[0];
// ERROR: Undefined offset: 5
echo $students[5];
// ERROR: Undefined index: key
echo $students[key];
?>Below, we will show you several methods to avoid the undefined offset error.
This function allows checking if the variable is set and is not null.
The example of using the isset function to avoid undefined offset error is as follows:
<?php
// Declare and initialize an array
// $students = ['Ann', 'Jennifer', 'Mary']
$students = [
0 => 'Ann',
1 => 'Jennifer',
2 => 'Mary',
];
if (isset($students[5])) {
echo $students[5];
} else {
echo "Index not present";
}
?>The output will show:
Index not present
The empty() function is used for checking if the variable or the index value inside an array is empty.
Here is an example:
<?php
// Declare and initialize an array
// $students = ['Rohan', 'Arjun', 'Niharika']
$students = [
0 => 'Ann',
1 => 'Jennifer',
2 => 'Mary',
];
if (!empty($students[5])) {
echo $students[5];
} else {
echo "Index not present";
}
?>The output will look as follows:
Index not present
This function is used for associative arrays that store data in the key-value pair form, and there is a value for each key.
The array_key_exists function is used for testing if a particular key exists in an array or not.
Here is an example:
<?php
// PHP program to illustrate the use
// of array_key_exists() function
function Exists($index, $array)
{
if (array_key_exists($index, $array)) {
echo "Key Found";
} else {
echo "Key not Found";
}
}
$array = [
"john" => 25,
"david" => 10,
"jack" => 20,
];
$index = "jack";
print_r(Exists($index, $array));
?>The output will be:
Key Found