I have a mySQL query that dumps into an array, is sorted and then displayed, and that works perfectly.
My problem is that I want to update these values, re-sort them and display. I've been able to update the values, but it's within the same for loop and so it doesn't re-sort. So then I close the loop and re-sort but it doesn't save the updates I made in the first loop. Help is much appreciated.
foreach ($arr as $mks){
if ($mks['Column1']==$Var) {$mks['Column2'] = $mks['Column2'] + 1;
}
My sorting code
foreach ($arr as $mks){
echo $mks['Column1'] . ", " . $mks['Column2'] . "<br>";
}
How do I get this to re-save into my array properly?! I've tried googling this for most of the morning but has lead to frustration.
I think this is what you need:
foreach ($arr as $key => $mks){
if ($mks[$key] == $Var) {
$arr[$key] = $mks+1;
}
}
Now, $arr will contain the modified array, and you can use / modify it further as you need.
I don't see any "sorting code" but you can try to use references "&" instead of copy vars in your foreach(s) :
foreach($arr as & $mks){
...
}
Instead of copying your cells it will to give you a reference and every modifications done on it will be saved in the array.
Try changing your array like this instead
foreach ($arr as $key => $mks){
if ($mks['Column1']==$Var) {$arr[$key]['Column2'] = $mks['Column2'] + 1;
}
Related
I have this code
if (isset($_POST['submit2']))
{
foreach ($_POST['check_list'] as $key) {
$input = implode(",", $key);
}
} /*end is isset $_POST['submit2'] */
echo $input;
it produces the error " implode(): Invalid arguments passed " when I change the implode arguments to implode(",", $_POST['check_list']) it works as intended.
Can someone clarify why? As far as I understand the $key variable should be the same as the $_POST['submit2'] isn't that what the as in the foreach does?
Sorry if it's a silly question, I'm self taught and sometimes details like that are hard to find online.
You seem confused at several levels, so let me clarify some of them:
You said 'As far as I understand the $key variable should be the same as the $_POST['submit2'] isn't that what the as in the foreach does?'. The answers are NO and NO:
The $key variable outside the foreach loop will contain the last element of the array that's stored in $_POST['check_list'], $_POST['submit2'] seems to be only used to check if is set and nothing else in your piece of code. What foreach does is to traverse any iterator variable (an array in your case) and set the current item in a variable ($key) in your case. So after the loop, $key will contain the last element of that array. For more information refer to the docs: [http://php.net/manual/en/control-structures.foreach.php]
implode expects the second parameter to be an array, it seems you're not providing an array, but any other type. Is the last item of $_POST['check_list'] actually an array?
If you're trying to 'glue' together all items of $_POST['check_list'], you don't need to iterate, you just use implode on that one: $input = implode(",", $_POST['check_list']);. Otherwise, i'm not sure what are you trying to do.
Maybe if you explain what are you trying to do, we can help better.
Foreach already iterates trough your values. You can either get the value and echo it from there or you can add it to another array input if thats what you need:
if (isset($_POST['submit2']))
{
foreach ($_POST['check_list'] as $key => $value) {
$input[] = 'Value #'. $key .' is ' . $value;
}
}
echo implode(",", $input);
You are saying that $_POST['check_list'] is an array if implode() works on it, so no need to loop to get individual items. To implode() the values:
echo implode(',', $_POST['check_list']);
To implode() the keys:
echo implode(',', array_keys($_POST['check_list']));
foreach() iterates over an array to expose each item and get the individual values and optionally keys one at a time:
foreach($_POST['check_list'] as $key => $val) {
echo "$key = $value<br />";
}
implode function needs array as second argument. You are passing string value as second argument. That's why it's not working.
I have an array of arrays, and I am trying to foreach loop through and insert new item into the sub arrays.
take a look below
$newarray = array(
array("id"=>1,"quantity"=>2),
array("id"=>1,"quantity"=>2),
array("id"=>1,"quantity"=>2),
);
foreach($newarray as $item){
$item["total"] = 9;
}
echo "<br>";
print_r($newarray);
The result just give me the original array without the new "total". Why ?
Because $item is not a reference of $newarray[$loop_index]:
foreach($newarray as $loop_index => $item){
$newarray[$loop_index]["total"] = 9;
}
The foreach() statement gives $item as an array: Not as the real value (consuming array). That meaning it can be read but not changed unless you then overwrite the consuming array.
You could use the for() and loop through like this: see demo.
Note: This goes all the way back to scopes, you should look into that.
I got a problem, I got a array from a sql query and I want to associate each value of this array to an index value.
array(16) { ["noCommande"]=> string(5) "49083" ["dateCommande"]=> string(19) "2007-02-21 18:24:04" ...
So here I just want to get back each value one per one. The array[i] doesn't work so I am a bit in trouble.
Thanks you for your support.
It's associative array, values are in
$array['noCommande'];
$array['dateCommande'];
etc.
If you want to ake a loop over array and write all values,
foreach ($array as $key => $value) {
echo $key . ': ' . $value; // echoes 'noCommande: 49083', etc.
}
You can iterate like below:-
foreach($your_array as $key=>$value){
echo $key.'-'.$value;
echo "<br/>";//for new line to show in a good manner
}
It will output like :- noCommande - 49083 and etc.
So I don't think I'm making full use of the foreach loop. Here is how I understand foreach.
It goes like foreach(arrayyouwanttoloopthrough as onevalueofthatarray)
No counter or incrementing required, it automatically pulls an array, value by value each loop, and for that loop it calls the value whatever is after the "as".
Stops once it's done with the array.
Should basically replace "for", as long as dealing with an array.
So something I try to do a lot with foreach is modify the array values in the looping array. But in the end I keep finding I have to use a for loop for that type of thing.
So lets say that I have an array (thing1, thing2, thing3, thing4) and I wanted to change it....lets say to all "BLAH", with a number at the end, I'd do
$counter = 0;
foreach($array as $changeval){
$counter++;
$changeval = "BLAH".$counter;
}
I would think that would change it because $changeval should be whatever value it's at for the array, right? But it doesn't. The only way I could find to do that in a] foreach is to set a counter (like above), and use the array with the index of counter. But to do that I'd have to set the counter outside the loop, and it's not even always reliable. For that I'd think it would be better to use a for loop instead of foreach.
So why would you use foreach over for? I think I'm missing something here because foreach has GOT to be able to change values...
Thanks
OH HEY One more thing. Are variables set in loops (like i, or key) accessible outside the loop? If I have 2 foreach loops like
foreach(thing as value)
would I have to make the second one
foreach(thing2 as value2) ]
or else it would have some problems?
You can use a reference variable instead:
foreach ($array as &$value)
{
$value = "foo";
}
Now the array is full of foo (note the & before $value).
Normally, the loop variable simply contains a copy of the corresponding array element, but the & (ampersand) tells PHP to make it a reference to the actual array element, rather than just a copy; hence you can modify it.
However, as #Tadeck says below, you should be careful in this case to destroy the reference after the loop has finished, since $value will still point to the final element in the array (so it's possible to accidentally modify it). Do this with unset:
unset($value);
The other option would be to use the $key => $value syntax:
foreach ($array as $key => $value)
{
$array[$key] = "foo";
}
To answer your second question: yes, they are subsequently accessible outside the loop, which is why it's good practice to use unset when using reference loop variables as in my first example. However, there's no need to use new variable names in subsequent loops, since the old ones will just be overwritten (with no unwanted consequences).
You want to pass by reference:
$arr = array(1, 2, 3, 4);
foreach ($arr as &$value)
{
$value = $value * 2;
}
// $arr is now array(2, 4, 6, 8)
The extended foreach syntax is like this:
foreach ($array as $key => $value) {
}
Using the $key, you can index the original array:
foreach ($array as $key => $value) {
$array[$key] = "BLAH";
}
Incrementing from 0 to ...
foreach($array as $changeval){
if (!isset($counter)) { $counter = 0; }
$counter++;
$changeval = "BLAH".$counter;
}
Using the index/key of the ARRAY
foreach($array as $key => $changeval){
$changeval = "BLAH".$key;
}
You can use the key when looping with foreach:
foreach ($array as $key => $value)
{
$array[$key] = "foo";
}
But note that using a reference like Will suggested will be faster for such a case - but anyway, the $key => $value-syntax is quite useful sometimes.
i am tring to put a loop to echo a number inside an echo ;
and i tried as bellow :
$array = array();
$result = mysql_query("SHOW TABLES FROM `st_db_1`");
while($row = mysql_fetch_row($result) ){
$result_tb = mysql_query("SELECT id FROM $row[0] LIMIT 1");
$row_tb=mysql_fetch_array($result_tb);
$array[] = $row[0];
$array2[] = $row_tb[0];
//checking for availbility of result_tb
/* if (!$result_tb) {
echo "DB Error, could not list tablesn";
echo 'MySQL Error: ' . mysql_error();
exit;
} */
}
natsort($array);
natsort($array2);
foreach ($array as $item[0] ) {
echo "<a href=show_cls_db.php?id= foreach ($array2 as $item2[0]){echo \"$item2[0]\"}>{$item[0]}<br/><a/>" ;
}
but php is not considering foreach loop inside that echo ;
please suggest me something
As mentioned by others, you cannot do loops inside a string. What you are trying to do can be achieved like this:
foreach ($array as $element) {
echo "<a href='show_cls_db.php?id=" . implode('', $array2) . "'>{$element}</a><br/>";
}
implode(...) concatenates all values of the array, with a separator, which can be an empty string too.
Notes:
I think you want <br /> outside of <a>...</a>
I don't see why you would want to used $item[0] as a temporary storage for traverser array elements (hence renamed to $element)
Just use implode instead of trying to loop the array,
foreach ($array as $item)
{
echo implode("",$array2);
}
other wise if you need to do other logic for each variable then you can do something like so:
foreach ($array as $item)
{
echo '<a href="show_details.php?';
foreach($something as $something_else)
{
echo $something_else;
}
echo '">Value</a>';
}
we would have to see the contents of the variables to understand what your trying to do.
As a wild guess I would think your array look's like:
array(
id => value
)
And as you was trying to access [0] within the value produced by the initial foreach, you might be trying to get the key and value separate, try something like this:
foreach($array as $id => $value)
{
echo $id; //This should be the index
echo $value; //This should be the value
}
foreach ($array as $item ) {
echo "<a href=\"show_cls_db.php?id=";
foreach ($array2 as $item2) { echo $item2[0]; }
echo "\">{$item[0]}<br/><a/>" ;
}
No offense but this code is... rough. Post it on codereview.stackexchange.com for some help re-factoring it. A quick tip for now would be to use PDO, and at the least, escape your inputs.
Anyway, as the answers have pointed out, you have simply echoed out a string with the "foreach" code inside it. Take it out of the string. I would probably use implode as RobertPitt suggested. Consider sorting and selecting your data from your database more efficiently by having mysql do the sorting. Don't use as $item[0] as that makes absolutely no sense at all. Name your variables clearly. Additionally, your href tag is malformed - you may not see the correct results even when you pull the foreach loop out of the echo, as your browser may render it all away. Make sure to put those quotes where they should be.