How to use multiple condition in one foreach loop? - php

Can I do this- "foreach($products as $product && $categories as $category)". multiple condition in one foreach loop? If not then how do I proceed this?

Use two loops:
foreach ($products as $product) {
foreach ($categories as $category) {
// using $product and $category
}
}

I had the same question today as the OP. I figured I can split up the problem by first merging the two arrays and then performing the actual foreach loop on the combined array.
This is the idea:
$combined_array = $products + $categories
foreach ($combined_array as $items) {. . .}
Practically speaking, I split the problem into two foreach loops, the first for the merging of the arrays and the second for the actual algorithm.
And indeed it does save me alot of space! Since it is much shorter to append one array to another array than to repeat a complicated foreach algorithm on two separate arrays consecutively.

If your two arrays have the same length, just use a for loop instead and access the elements using the current index.
You just have to make sure, that the indezies are matching in the two arrays.
Its not possible to achieve what you are trying using a foreach loop.
for ($i = 0; $i < count($arr1); $i++) {
// do whatever you want with $arr1[$i] and $arr2[$i]
}
If your array have the same length, but the indizies may differ and you still want them to be on par, use array_values() before the loop to reindex both arrays.
This will only work for index based arrays!

you can't do that.
but what can you do is to loop inside the loop
foreach($categories as $category)
{
foreach($products as $product)
{
}
}

foreach( $codes as $code and $names as $name ) { }
That is not valid.
You probably want something like this...
foreach( $codes as $index => $code ) {
echo '<option value="' . $code . '">' . $names[$index] . '</option>';
}

Related

PHP Looping through each item on a one dimensional array

If I have array like this myarray[0]['field1','field2','field3'];
I know its basically one row and has nothing to loop through, but i need it to loop through the values rather than the whole array. In this case it would need to loop 3x but if there were 10 fields, it should loop 10x.
I've been doing this but it feels too complicated for something so simple. Is there a function that is eluding me on google for this?
foreach (myarray[0][field1] as $item){
//do something
}
foreach (myarray[0][field2] as $item){
//do something
}
foreach (myarray[0][field3] as $item){
//do something
}
Use nested loops:
foreach ($myarray[0] as $field => $field_array){
foreach ($myarray[0][$field] as $item) {
//do something
}
}
You have a 2-dimensional array, but you want to only consider the second dimension? So treat the first dimension as a variable:
foreach ($myarray[0] as $item){
echo $item;
}
If you want to know the field name and value, then:
foreach ($myarray[0] as $key=>$value){
echo $key . ' = ' . $value;
}
foreach ($myarray[0] as $field => $field_array){
foreach ($field_array as $item) {
//do something
}
}

PHP foreach insert array

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.

PHP - Looping through an object keys, one cycle per key

I have this object containing one row and many keys/variables with numbered names.
I need to pass each of them one at a time to another function. How do I loop through the keys instead of the rows?
The code would look like this:
foreach ($object['id'] as $row):
$i++;
$data['myInfo'][$i] = $this->get_data->getInfo('data1', 'id', $row->{'info'.$i.'_id'});`
but this obviously won't work since it's looping through the rows/instances of an object, and I have only one row in my $object['id'] object (with info1_id, info2_id, info3_id, info4_id... etc keys), so the loop stops after just one cycle. And I really don't feel like typing all of that extra code by hand, there's gotta be solution for this. :)
You can just iterate through your object like an array :
foreach ($object['id'] as $row) {
foreach ($row as $k => $v) {
$id = substr($k, 4, strpos($k, '_')-4);
$data['myInfo'][$id] = $this->get_data->getInfo('data1', 'id', $v);`
}
}
Thanks for the directions Alfwed, I didn't know you could use foreach loop for anything other than instances of an object or arrays (only started learning php a week or so ago), but now it looks pretty straight forward. that's how I did it:
foreach ($object['id'] as $row):
foreach ($row as $k=>$v):
$i++;
if ($k == print_r ('info'.$i.'_id',true)){
$data['myinfo'][$i] = $this->get_db->getRow('products', 'id','info'.$i.'_id');
<...>
in my case, I knew how many and where were those values, so I didn't have to worry about index values too much.

Updating and Sorting a Multidimensional PHP Array

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;
}

How can I find out how many times a foreach construct loops in PHP, without using a "counter" variable?

If I have a foreach construct, like this one:
foreach ($items as $item) {
echo $item . "<br />";
}
I know I can keep track of how many times the construct loops by using a counter variable, like this:
$counter = 0;
$foreach ($items as $item) {
echo $item.' is item #'.$counter. "<br />";
$counter++;
}
But is it possible to do the above without using a "counter" variable?
That is, is it possible to know the iteration count within the foreach loop, without needing a "counter" variable?
Note: I'm totally okay with using counters in my loops, but I'm just curious to see if there is a provision for this built directly into PHP... It's like the awesome foreach construct that simplified certain operations which are clunkier when doing the same thing using a for construct.
No it's not possible unless your $items is an array having contiguous indexes (keys) starting with the 0 key.
If it have contiguous indexes do:
foreach ($items as $k => $v)
{
echo $k, ' = ', $v, '<br />', PHP_EOL;
}
But as others have stated, there is nothing wrong using a counter variable.
There's no easier way - that's kinda what count variables are for.
I'm assuming that you want to know the current count during the loop. If you just need to know it after, use count($items) as others have suggested.
You could tell how many time it WILL loop or SHOULD have looped by doing a
$loops = count($items);
However that will only work if your code does not skip an iteration in any way.
foreach loops N times, where N is just the size of the array. So you can use count($items) to know it.
EDIT
Of course, as noticed by Bulk, your loop should not break (or maybe continue, but I would count a continue as a loop, though shorter...)

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