Remove Array value - php

[0] => LR-153-TKW
[1] => Klaten
[2] => Rectangular
[3] => 12x135x97
I have an array looking like this. and I want to completely remove 12x135x97 to the mother array so how would i do this?

You can use unset($arr[3]);. It will delete that array index. Whenever you want to delete an array value, you can use PHP unset() method.
As you were asked into your comment:
basically i just want to remove all index that have "X**X" this pattern digit 'x' digit
Here is the code that you can use:
$arr = array("LR-153-TKW", "Klaten", "Rectangular", "12x135x97", "xxxx");
$pattern_matched_array = preg_grep("/^[0-9]+x[0-9]+x[0-9]*/", $arr);
if(count($pattern_matched_array) > 0)
{
foreach($pattern_matched_array as $key => $value)
{
unset($arr[$key]);
}
}
print_r($arr);

PHP has unset() function. You can use it for deleting a variable or index of array.
unset($your_var[3]);
See http://php.net/manual/en/function.unset.php

You have many options:
if you know the array key then you can do this
unset($arrayName[3]);
or if it's always at the end of your array
array_pop($arrayName);
this will remove the last value out of your array

Use unset, to find it you can do this:
for($i = 0; $i < count($array); $i++){
if($i == "12x135x97"){
unset($array[i]);
break;
}
}
Unless you know the key, in which case you can do:
unset($array[3]);
its not the most time efficient if you array is thousands of items long, but for this job it will suffice.
To turn it into a method, would make for better coding.
function removeItem($item){
for($i = 0; $i < count($array); $i++){
if($i == $item){
unset($array[i]);
break;
}
}
return $array;
}
and call it like:
removeItem("12x135x97");

Related

How to remove an all the elements in an array through iteration

I have an array $scripts_stack = []; that holds arrays:
$array_item = array('script' => $file_parts, 'handle' => $file_name, 'src' => $url);
array_push($scripts_stack, $array_item);
<?php
for ($i = 0; $i < sizeof($scripts_stack); $i++) {
$child_array = $scripts_stack[$i];
if (is_array($child_array)) {
// Do things with $child_array,
// then remove the child array from $scripts_stack when done with (BELOW)
unset($scripts_stack[$i]);
}
}
echo "Array Size : " . (sizeof($scripts_stack)); // AT THE END
However, my attemts only remove half the elements. No matter what I try, it's only half the items that get removed. sizeof($scripts_stack) is always half the size of what it was at the start.
I'm expecting that it would be empty // AT THE END
Why is it that I only get half the elements in the array removed?
Thank you all in advance.
As mentioned in other answers, $i increments but the sizeof() the array shrinks. foreach() is probably the most flexible looping for arrays as it exposes the actual key (instead of hoping it starts at 0 and increments by 1) and the value:
foreach ($scripts_stack as $key => $child_array) {
if (is_array($child_array)) {
// Do things with $child_array,
// then remove the child array from $scripts_stack when done with (BELOW)
unset($scripts_stack[$key]);
}
}
Just FYI, the way you're doing it with for almost works. You just need to establish the count before the loop definition, rather than recounting in the continuation condition.
$count = sizeof($scripts_stack);
for ($i = 0; $i < $count; $i++) { // ...
Still, I think it would be better to just use a different type of loop as shown in the other answers. I'd personally go for foreach since it should always iterate every element even if some indexes aren't present. (With the way you're building the array, it looks like the indexes should always be sequential, though.)
Another possibility is to shift elements off of the array rather than explicitly unsetting them.
while ($child_array = array_shift($scripts_stack)) {
// Do things with $child_array,
}
This will definitely remove every element from the array, though. It looks like $child_array should always be an array, so the is_array($child_array) may not be necessary, but if there's more to it that we're not seeing here, and there are some non-array elements that you need to keep, then this won't work.
You advanced $i while the array is getting shrinked, but in the same time you jump over items in your array.
The first loop is where $i == 0, and then when you removed item 0 in your array, the item that was in the second place has moved to the first place, and your $i == (so you will not remove the item in the current first place, and so on.
What you can do is use while instead of for loop:
<?php
$i = 0;
while ($i < sizeof($scripts_stack)) {
$child_array = $scripts_stack[$i];
if (is_array($child_array)) {
// Do things with $child_array,
// then remove the child array from $scripts_stack when done with (BELOW)
unset($scripts_stack[$i]);
} else {
$i++;
}
}
echo "Array Size : " . (sizeof($scripts_stack)); // AT THE END
May be you can use this script.It's not tested.
foreach($array as $key => $value ) {
unset($array[$key]);
echo $value." element is deleted from your array</br>";
}
I hope , it will help you.
The problem root is in comparing $i with sizeof($scripts_stack). Every step further sizeof($scripts_stack) becomes lower (it calculates at every step) and $i becomes higher.
The workaround may look like this:
<?php
$scripts_stack = [];
$array_item = array('script' => 1, 'handle' => 2, 'src' => 3);
array_push($scripts_stack, $array_item);
array_push($scripts_stack, $array_item);
array_push($scripts_stack, $array_item);
array_push($scripts_stack, $array_item);
array_push($scripts_stack, $array_item);
while (sizeof($scripts_stack) > 0) {
$child_array = array_shift($scripts_stack);
if (is_array($child_array)) {
// Do things with $child_array,
// then remove the child array from $scripts_stack when done with (BELOW)
}
}
echo "Array Size : " . (sizeof($scripts_stack)); // AT THE END
https://3v4l.org/N2p3v

How to implode a generator?

I have a PHP generator which generates some $key => $value.
Is there an "easy" way to implode the values (by passing the generator name)? Or to transform it to an array?
I can do this with a couple of lines of code, but are there some builtins functions to accomplish this?
You can use iterator_to_array function for the same, have a look on below example:
function gen_one_to_three() {
for ($i = 1; $i <= 3; $i++) {
// Note that $i is preserved between yields.
yield $i;
}
}
$generator = gen_one_to_three();
$array = iterator_to_array($generator);
print_r($array);
Output
Array
(
[0] => 1
[1] => 2
[2] => 3
)
One has to keep in mind that
A generator is simply a function that returns an iterator.
For instance:
function digits() {
for ($i = 0; $i < 10; $i++) {
yield $i;
}
}
digits is a generator, digits() is an iterator.
Hence one should search for "iterator to array" functions, to find iterator_to_array (suggested by Chetan Ameta )

Finding entry in array and putting it first or swapping with the first array entry

I have a PHP array full of arrays and what I want to do is search through this array for the chosen entry and swap it with the first entry in the array if that makes sense...
So for my example below I have chosen Penny so I would like her to either go before Bob or swap places with Bob.
My array looks like this:
$people = array(
array('Bob', 'Wilson'),
array('Jill', 'Thompson'),
array('Penny', 'Smith'),
array('Hugh', 'Carr')
);
I have tried using array_search but I don't think I am doing it correctly.
for ($i = count($array) - 1; $i > 0; $i--) {
if ($array[$i][0] == $first_name) { // Or by whatever you want to search? in_array...?
$searched_array = array_splice($array, $i, 1);
array_unshift($array, $searched_array[0]);
}
}
This is for prepending. If you want to swap, see the answer of #IAmNotProcrastinating
function swap (&$ary,$fromIndex,$toIndex=0)
{
$temp=$ary[$toIndex];
$ary[$toIndex]=$ary[$fromIndex];
$ary[$fromIndex]=$temp;
}
foreach ($elements as $key => $element) {
/* do the search, get the $key and swap */
}

Replace non-specified array values with 0

I want to replace all array values with 0 except work and home.
Input:
$array = ['work', 'homework', 'home', 'sky', 'door']
My coding attempt:
$a = str_replace("work", "0", $array);
Expected output:
['work', 0, 'home', 0, 0]
Also my input data is coming from a user submission and the amount of array elements may be very large.
A bit more elegant and shorter solution.
$aArray = array('work','home','sky','door');
foreach($aArray as &$sValue)
{
if ( $sValue!='work' && $sValue!='home' ) $sValue=0;
}
The & operator is a pointer to the particular original string in the array. (instead of a copy of that string)
You can that way assign a new value to the string in the array. The only thing you may not do is anything that may disturb the order in the array, like unset() or key manipulation.
The resulting array of the example above will be
$aArray = array('work','home', 0, 0)
A loop will perform a series of actions many times. So, for each element in your array, you would check if it is equal to the one you want to change and if it is, change it. Also be sure to put quote marks around your strings
//Setup the array of string
$asting = array('work','home','sky','door')
/**
Loop over the array of strings with a counter $i,
Continue doing this until it hits the last element in the array
which will be at count($asting)
*/
for($i = 0; $i < count($asting);$i++){
//Check if the value at the 'ith' element in the array is the one you want to change
//if it is, set the ith element to 0
if ($asting[$i] == 'work' || $asting[$i] == 'home')
$asting[$i] = 0;
}
Here is some suggested reading:
http://www.php.net/manual/en/language.types.array.php
http://www.php.net/manual/en/language.control-structures.php
But if you are struggling on stuff such as looping, you may want to read some introductory programming material. Which should help you really understand what's going on.
A bit other and much quicker way, but true, need a loop:
//Setup the array of string
$asting = array('bar', 'market', 'work', 'home', 'sky', 'door');
//Setup the array of replacings
$replace = array('home', 'work');
//Loop them through str_replace() replacing with 0 or any other value...
foreach ($replace as $val) $asting = str_replace($val, 0, $asting);
//See what results brings:
print_r ($asting);
Will output:
Array
(
[0] => bar
[1] => market
[2] => 0
[3] => 0
[4] => sky
[5] => door
)
An alternative using array_map:
$original = array('work','home','sky','door');
$mapped = array_map(function($i){
$exclude = array('work','home');
return in_array($i, $exclude) ? 0 : $i;
}, $original);
you may try array_walk function:
function zeros(&$value)
{
if ($value != 'home' && $value != 'work'){$value = 0;}
}
$asting = array('work','home','sky','door','march');
array_walk($asting, 'zeros');
print_r($asting);
You can also give array as a parameter 1 and 2 on str_replace...
Just a small point to the for loop. Many dont realize the second comparing task is done every new iteration. So if it was a case of big array or calculation you could optimize loop a bit by doing:
for ($i = 0, $c = count($asting); $i < $c; $i++) {...}
You may also want to see http://php.net/manual/en/function.array-replace.php for original problem unless the code really is final :)
Try This
$your_array = array('work','home','sky','door');
$rep = array('home', 'work');
foreach($rep as $key=>$val){
$key = array_search($val, $your_array);
$your_array[$key] = 0;
}
print_r($your_array);
There are a few techniques on this page that make zero iterated function calls -- which is good performance-wise. For best maintainability, I recommend separating your list of targeted string as a lookup array. By modifying the original array values by reference, you can swiftly replace whole strings and null coalesce non-targeted values to 0.
Code: (Demo)
$array = ['work', 'homework', 'home', 'sky', 'door'];
$keep = ['work', 'home'];
$lookup = array_combine($keep, $keep);
foreach ($array as &$v) {
$v = $lookup[$v] ?? 0;
}
var_export($array);
Output:
array (
0 => 'work',
1 => 0,
2 => 'home',
3 => 0,
4 => 0,
)
You can very easily, cleanly extend your list of targeted strings by merely extending $keep.
If you don't want a classic loop, you can use the same technique without modifying the original array. (Demo)
var_export(
array_map(fn($v) => $lookup[$v] ?? 0, $array)
);
this my final code
//Setup the array of string
$asting = array('work','home','sky','door','march');
/**
Loop over the array of strings with a counter $i,
Continue doing this until it hits the last element in the array
which will be at count($asting)
*/
for($i = 0; $i < count($asting); $i++) {
//Check if the value at the 'ith' element in the array is the one you want to change
//if it is, set the ith element to 0
if ($asting[$i] == 'work') {
$asting[$i] = 20;
} elseif($asting[$i] == 'home'){
$asting[$i] = 30;
}else{
$asting[$i] = 0;
}
echo $asting[$i]."<br><br>";
$total += $asting[$i];
}
echo $total;

PHP: Getting to a key in mulitdimensional array?

I have an array like
$myArray =array
(
"0"=>array("dogs",98),
"1"=>array("cats",56),
"2"=>array("buffaloes",78)
)
How can I get a key by providing a value?
e.g. if i search for "buffaloes" array_search may return "2".
Thanks
$myArray =array
(
"0"=>array("dogs",98),
"1"=>array("cats",56),
"2"=>array("buffaloes",78)
);
function findInArray($term, $array) {
foreach($array as $key => $val) {
if(in_array($term, $val, true)) {
return $key;
}
}
}
echo findInArray('buffaloes', $myArray); // 2
echo findInArray(78, $myArray); // 2
function asearch($key, $myArray) {
for ($i = 0; $i < sizeof($myArray); $i++) {
if ($myArray[$i][0] == $key) {
return $i;
}
}
return -1; # no match
}
Though, you'd probably want to restructure your array to:
$myarray = array(
'dogs' => 98,
'cats' => 56,
'buffaloes' => 78
);
And just do:
$myArray['buffaloes']; # 78
The only way you can do it is to iterate over every item and preform a Linear Search
$i = -1;
foreach ($myArray as $key => $item){
if ( $item[0] == 'buffaloes' ){
$i = $key;
break;
}
}
//$i now holds the key, or -1 if it doesn't exist
As you can see, it is really really inefficient, as if your array has 20,000 items and 'buffaloes' is the last item, you have to make 20,000 comparisons.
In other words, you need to redesign your data structures so that you can look something up using the key, for example a better way may be to rearrange your array so that you have the string you are searching for as the key, for example:
$myArray['buffaloes'] = 76;
Which is much much faster, as it uses a better data structure so that it only has to at most n log n comparisons (where n is the number of items in the array). This is because an array is in fact an ordered map.
Another option, if you know the exact value of the value you are searching for is to use array_search
I never heard of built in function. If you want something more general then above solutions you shold write your own function and use recursion. maybe array_walk_recursive would be helpful
You can loop over each elements of the array, testing if the first element of each entry is equal to "buffaloes".
For instance :
foreach ($myArray as $key => $value) {
if ($value[0] == "buffaloes") {
echo "The key is : $key";
}
}
Will get you :
The key is : 2
Another idea (more funny ?), if you want to whole entry, might be to work with array_filter and a callback function that returns true for the "bufalloes" entry :
function my_func($val) {
return $val[0] == "buffaloes";
}
$element = array_filter($myArray, 'my_func');
var_dump($element);
Will get you :
array
2 =>
array
0 => string 'buffaloes' (length=9)
1 => int 78
And
var_dump(key($element));
Gves you the 2 you wanted.

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