I keep getting undefined offset.. what would be the problem with this?
for($m=0; $m<=count($data); $m++){ // (this is where it points)
if(date("m-Y",strtotime($data['data'][$i]['date_d'])) == $curdate)
$sum.$cmonth +=1;
else
$sum.$cmonth = 0;
}
That is because , adding a <= will make your loop iterate till the non-existent index of the array. , Rewrite like this.
for($i=0; $i<count($data); $i++){ // (this is where it points)
if(date("m-Y",strtotime($data['data'][$i]['date_d'])) == $curdate)
$sum.$cmonth +=1;
else
$sum.$cmonth = 0;
}
I recommend a foreach instead.
foreach($data as $k=>$v)
{
}
I see your array to be multidimensional and you are running the loop on second index so do like
for($m=0; $m<count($data['data']); $m++){
This will consider the length of the array(if there is any) named data inside the $data variable.
And change your $i to $m(if you are trying to traverse that array usinf the loop) like
if(date("m-Y",strtotime($data['data'][$m]['date_d'])) == $curdate)
Related
Lets say for example I have a result set from a MySQL query that has produced values: 3,5,10,11 and so forth...
I would like to iterate through a for loop in PHP but exclude the any iteration that would equal any number in results of my MySQL query.
As it stands I currently have:
for($i = 1; $i <= $num_rows; $i++)
{
if($i == 3 or $i == 5)
{
continue;
}
//Rest of loop...
As you will all appreciate hard coding these values is very time consuming and not very efficient. If any one could help it would be greatly appreciated.
If you can gather automatically those values you are currently hard coding, you can use in_array($search, $array[, $strict])
Like this :
$bypass = array(3, 5);
for($i = 1; $i <= $num_rows; $i++)
{
if( in_array($i, $bypass) )
{
continue;
}
// rest of the loop
}
PS : I prefer much more the "Dont Panic" answer, which doesn't use too many loops. (in_array will loop through the array to find your value). See his answer : https://stackoverflow.com/a/38880057/3799829
If your query results are returned as an array you can use
if(in_array($i, $results)) to do a check of $i against the results
Add your values into an array while you fetch your query results. I used PDO here for example, but you should be able to adapt it to whichever database extension you're using:
while ($row = $stmt->fetchObject()) {
$exclude[$row->value] = true;
// whatever else you're doing with the query results
}
If you use the values as keys in the array of things you want to skip, checking for them in your for loop should be more efficient than using in_array.
for($i = 1; $i <= $num_rows; $i++) {
if (isset($exclude[$i])) continue;
// rest of loop
I've this these array values :
$cart_item['addons'][0]['price'] = '52';
$cart_item['addons'][1]['price'] = '34';
$cart_item['addons'][2]['price'] = '12';
......
....
I want that each values are at 0 like :
$cart_item['addons'][0]['price'] = '0';
$cart_item['addons'][1]['price'] = '0';
$cart_item['addons'][2]['price'] = '0';
....
...
So I try this code :
for ($i=0; $i > 0 ; $i++) {
$cart_item['addons'][$i]['price'] = '0';
}
But it does not work. Thanks for your help !
Try this simple solution:
$count=count($cart_item['addons']);
for($i=0; $i<$count;$i++ ){
$cart_item['addons'][$i]['price'] = '0';
}
If your array is big enough, putting count() function inside for loop is being a crazy coconut. It will be much, much slower. Please use the count outside the loop:
$count = count($cart_item['addons'])
for($i=0; $i<$count;$i++ ){
$cart_item['addons'][$i]['price'] = '0';
}
You have to loop more often to achive this:
foreach($cart_item['addons'] as &$addons {
foreach($addons as &$addon) {
$addon['price'] = 0;
}
}
You can iterate over $cart_item['addons'], like so:
foreach ($cart_item['addons'] AS $key => &$value) {
$value['price'] = 0;
}
(Your code does not get executed, because $i is never changed and so is never > 0)
Also note that you need to use the reference (&$value) when changing the array in foreach loop.
There are three parts to your for loop: for(counter | test | action){}. It might be useful for you to look at this guide about for loops. You initialise your variable:
$i = 0;
then you do a logical check (the test part):
$i > 0;
If we substitute the the variable ($i) for the value it holds (0) we get:
0 > 0
which will never be true and thus you will never get to the final part (action) of the for loop:
$i++;
Instead you could make it loop until it has moved through your entire array like this:
$elementCount = count(cart_item['addons']);
for($i=0; $i < $elementCount; $i++){
$cart_item['addons'][$i]['price'] = '0';
}
Each time it loops we add one to $i until we reach the stopping condition where $i is no longer less than the number of items in the array.
It's also worth noting that PHP has a number of functions that help working with arrays.
I asked a similar question earlier but I couldn't get a clear answer to my issue. I have a function "isParent" that gets 2 pieces of data. Each 1 of the 2 gets a string separating each value with a , or it just gets a plain int and then checks if the first value given is a parent of the second.
I pull the 2 bits of data in and explode them but when I go through my nested for loop and try to test
$toss = $arr1[$i];
print_r($toss);
It comes up blank. I have no idea what the issue is: Here is the full code of the function...
function isParent($parent, $child)
{
$parentArr = explode(',', $parent);
$childArr = explode(',',$child);
//Explode by Comma here. If array length of EITHER parentArr or childArr > 1 Then throw to an Else
if(count($parentArr) <= 1 && count($childArr) <= 1) //If explode of either is > 1 then ELSE
{
$loop = get_highest_slot(15);
for($i = $loop; $i > 0; $i--)
{
$temp = get_membership_from_slot($i,'id_parent','id_child');
if($temp['id_parent'] == $parent && $temp['id_child'] == $child)
{
return 1;
}
}
}
else //set up a for loop in here so that you traverse each parentArr value and for each iteration check all child values
{
$i = count($parentArr);
$c = count($childArr);
for(;$i >=0;$i--) //Loop through every parent
{
for(;$c >=0;$c--)
{
echo '<br>$i = ';
print_r($i);
echo '<br><br>Parent Arr at $i:';
$toss = $parentArr[$i];
echo $toss;
echo '<br>';
print_r($childArr);
echo '<br><br>';
if(isParent($parentArr[$i],$childArr[$c])) //THIS CAUSES AN INFINITE YES! Learn how to pull an array from slot
{
return 1;
}
}
}
}
return 0;
}
You are missing some code for the slot procedures. Apart from that, you probably need to use a different variable for the inner for loop. because $c will be 0 after the first iteration of $i.
Thanks for the help! The issue was in the recursive call back to the top of the function. It was tossed empty slots and when comparing 2 empty slots it returned a false positive. A quick !empty() check fixed it.
I'm trying to print an array until it's empty.
Here is my code:
for ($i=0; $array[0][$i]!=NULL; ++$i){
echo $array[0][$i];
}
However it looks like it performs the echo one extra time, I don't know why ?
Here's my output for an array that contains data up to array[0][2].
I am sure that array[0][3] is empty, I tried it with if(array[0][3]==NULL)
Test 0
Test 1
Test 2
( ! ) Notice: Undefined offset: 3 in C:\... on line 9
Any idea ?
You should use the arrays length when you loop... Or try this instead:
foreach($array[0] as $val) {
echo $val;
}
It makes perfect sense, really. PHP can not magically know that the next id (in your example, index number '3') is not set, it has to access the variable to determine that. That's also why you get the notice.
In short, it does not execute the body of the for loop, but it has to execute the test to determine whether or not to continue.
Anyway, use a foreach loop, or calculate the number of items in the array first and increment $i till they match.
Possible alternatives to you code that should actually work.
foreach($array[0] as $val)
if($val===null)
break;
else
echo $val;
or
$arrlen=count($array[0]);
for($i=0;$i<$arrlen;$i++)
if($array[0][$i]===null)
break;
else
echo $array[0][$i];
or even
$i=0;
while($array[0][$i]!==null) { //not recommended, can cause infinite loop
echo $array[0][$i];
$i++;
}
The reason why it's throwing an error is because an array index that does not exist is not equal to NULL. You can modify your code to this:
for ($i=0; isset($array[0][$i]); ++$i){
echo $array[0][$i];
}
Or try this instead:
$ctr = count($array[0]);
for ($i = 0; $i < $ctr; $i++) {
echo $array[0][$i];
}
The loop should finish after reaching the end of the array.
say I have an array
$test_backwards=array("something1","something2","something3");
this is just a testing example and it's important to note that values will be added dinamically in my final array. so is it possible to dynamically return values from behind, namely starting from the last element?
something like this but backwards
for($i=0;$i<count($test_backwards);$i++) {
echo $test_backwards.'<br>';
}
Just start at the end and decrement your index:
for ($i = count($test_backwards) - 1; $i >= 0; $i--) {
echo $test_backwards[$i].'<br>';
}
or use array_reverse() (slower):
$test_backwards = array_reverse($test_backwards);
for ($i = 0; $i < count($test_backwards); $i++) {
echo $test_backwards[$i].'<br>';
}
You can also use array_pop(), if you do not need to keep this array. Or you can assign it to a temp array and then array_pop it, it will get and delete value from last.
$temp = $test_backwards;
while(($item = array_pop($temp)) !== NULL ) {
echo $item;
}