Insert value from one array to another and keep their keys - php

I have 2 Arrays :
Array
(
[1] => image1
[4] => image2
)
Array
(
[0] => title 1
[2] => title 2
[3] => title 3
)
I just want to merge these arrays and KEEP their key ([1] => image1 will also be at [1] in the new array)
Any idea please ? Thanks !

That should work :)
foreach ($array2 as $key => $value)
{
$array1[$key] = $value;
}
The keys & values from array2 will be appended at the end. If your array is just numeric, you can bring it to the right order with array_sort().

I think this function works. You have to use only numeric keys tough
$array1;
$array2;
array_weird_merge($array1, $array2){
$result = array();
//get the keys of each array
$keys1 = array_keys($array1);
$kesy2 = array_keys($array2);
//get the max keys of the 2 arrays
$max = max($key1, $key2);
//we go trough all the possible values
for ($i=0; $i<$max;$i++){
//if the array 1 has an element in the
//$i position, we put it in the result
//if not, then we check in the second
//array. (we give priority to the array
//that comes first)
if(isset($array1[$i])){
$result[$i] = $array1[$i];
}else if(isset($array2[$i])){
$result[$i] = $array2[$i];
}
}
return $result;
}

Related

Count how many times a value appears in this array?

I have this php array named $ids:
Array (
[0] => Array ( [id] => 10101101 )
[1] => Array ( [id] => 18581768 )
[2] => Array ( [id] => 55533322 )
[3] => Array ( [id] => 55533322 )
[4] => Array ( [id] => 64621412 )
)
And I need to make a new array containing each $ids id value, as the new keys, and the times each one appears, as the new values.
Something like this:
$newArr = array(
10101101 => 1,
18581768 => 1,
55533322 => 2,
64621412 => 1,
);
This is what I have:
$newArr = array();
$aux1 = "";
//$arr is the original array
for($i=0; $i<count($arr); $i++){
$val = $arr[$i]["id"];
if($val != $aux1){
$newArr[$val] = count(array_keys($arr, $val));
$aux1 = $val;
}
}
I supose array_keys doesn't work here because $arr has the id values in the second dimension.
So, how can I make this work?
Sorry for my bad english and thanks.
array_column will create an array of all the elements in a specific column of a 2-D array, and array_count_values will count the repetitions of each value in an array.
$newArr = array_count_values(array_column($ids, 'id'));
Or do it by hand like this where $arr is your source array and $sums is your result array.
$sums = array();
foreach($arr as $vv){
$v = $vv["id"];
If(!array_key_exists($v,$sums){
$sums[$v] = 0;
}
$sums[$v]++;
}
You can traverse your array, and sum the id appearance, live demo.
$counts = [];
foreach($array as $v)
{
#$counts[$v['id']] += 1;
}
print_r($counts);

Remove duplicates from a multi-dimensional array based on 2 values

I have an array that looks like this
$array = array(
array("John","Smith","1"),
array("Bob","Barker","2"),
array("Will","Smith","2"),
array("Will","Smith","4")
);
In the end I want the array to look like this
$array = array(
array("John","Smith","1"),
array("Bob","Barker","2"),
array("Will","Smith","2")
);
The array_unique with the SORT_REGULAR flag checks for all three value. I've seen some solutions on how to remove duplicates based on one value, but I need to compare the first two values for uniqueness.
Simple solution using foreach loop and array_values function:
$arr = array(
array("John","Smith","1"), array("Bob","Barker","2"),
array("Will","Smith","2"), array("Will","Smith","4")
);
$result = [];
foreach ($arr as $v) {
$k = $v[0] . $v[1]; // considering first 2 values as a unique key
if (!isset($result[$k])) $result[$k] = $v;
}
$result = array_values($result);
print_r($result);
The output:
Array
(
[0] => Array
(
[0] => John
[1] => Smith
[2] => 1
)
[1] => Array
(
[0] => Bob
[1] => Barker
[2] => 2
)
[2] => Array
(
[0] => Will
[1] => Smith
[2] => 2
)
)
Sample code with comments:
// array to store already existing values
$existsing = array();
// new array
$filtered = array();
foreach ($array as $item) {
// Unique key
$key = $item[0] . ' ' . $item[1];
// if key doesn't exists - add it and add item to $filtered
if (!isset($existsing[$key])) {
$existsing[$key] = 1;
$filtered[] = $item;
}
}
For fun. This will keep the last occurrence and eliminate the others:
$array = array_combine(array_map(function($v) { return $v[0].$v[1]; }, $array), $array);
Map the array and build a key from the first to entries of the sub array
Use the returned array as keys in the new array and original as the values
If you want to keep the first occurrence then just reverse the array before and after:
$array = array_reverse($array);
$array = array_reverse(array_combine(array_map(function($v) { return $v[0].$v[1]; },
$array), $array));

Comparing array values of just 1 array

Here is my array:
Array
(
[0] => Array
(
[0] => Array
(
[0] => West
[1] => 4
)
[1] => Array
(
[0] => South west
[1] => 20
)
)
)
What I want to achieve is be able to compare $array[0][0][1] and $array[0][1][1]. So whichever is lesser comes first and I get the value. So in this case I know that 4 is lesser so I get West first then South west is next. It should be dynamic since we can get more than 2.
This a simple example you can use :
$arr = array(
array("name"=>"Bob","age"=>8,"colour"=>"red"),
array("name"=>"Greg","age"=>12,"colour"=>"blue"),
array("name"=>"Andy","age"=>5,"colour"=>"purple"));
$sortArray = array();
foreach($arr as $val){
foreach($val as $key=>$value){
if(!isset($sortArray[$key])){
$sortArray[$key] = array();
}
$sortArray[$key][] = $value;
}
}
$orderby = "age"; //change this to whatever key you want from the array
array_multisort($sortArray[$orderby],SORT_ASC,$arr);
print_r($arr);
Assuming the depth of the array structure remains the same, and you only want the very lowest, you can use a simple foreach.
function findLowestName($array) {
$lowest = 0; // variable to hold the index of the lowest entry.
// go through every entry in the first array member
foreach($array[0] as $key => $value) {
// if this entry is lower than the 'current' lowest, mark this as the new lowest
if($value[1] < $array[0][$lowest]) {
$lowest = $key;
}
}
return $array[0][$lowest][0];
}
Built as a function, so you can include it, and call the function, passing it the array as a parameter.

How to skip iteration in foreach inside foreach

I have an array of values, and i want to insert the values to another array but with an if condition, if the "if" is true I want to skip the iteration.
Code:
$array=array(array(1=>11,2=>22,3=>23,4=>44,5=>55));
$insert=array();
foreach($array as $k1=>$v1)
{
foreach($v1 as $k2=>$v2)
{
if($v2==23)
{
break;
}
}
$insert[]=$v1;
}
final result should look like that
Array
(
[0] => Array
(
[1] => 11
[2] => 22
[3] => 44
[4] => 55
)
)
I tried using: break,return,continue...
Thanks
There are a few ways to do this. You can loop over the outer array and use array_filter on the inner array to remove where the value is 23 like this (IMO preferred; this also uses an array of $dontWant numbers so it is easier to add or change numbers later):
<?php
$array = array(array(1=>11,2=>22,3=>23,4=>44,5=>55));
$insert = array();
//array of numbers you don't want
$dontWant = array(23);
//loop over outer array
foreach($array as $subArray){
//add to $insert a filtered array
//subArray is filtered to remove where value is in $dontWant
$insert[] = array_filter($subArray, function($val) uses ($dontWant) {
//returns true if the value is not in the array of numbers we dont want
return !in_array($val, $dontWant);
});
}
//display final array
echo '<pre>'.print_r($insert,1).'</pre>';
Or you can reference the first key to add to a sub array in $insert like (which is a little more like what your code is trying to do and show that you are not too far off):
<?php
$array = array(array(1=>11,2=>22,3=>23,4=>44,5=>55));
$insert = array();
//loop over outer array
foreach($array as $k1=>$v1){
//add an empty array to $insert
$insert[$k1] = array();
//loop over inner array
foreach($v1 as $k2=>$v2){
//if the inner array value is not 23
if($v2 != 23){
//add to inner array in insert
$insert[$k1][] = $v2;
}
}
}
//display the result
echo '<pre>'.print_r($insert,1).'</pre>';
Both of these methods would produce the same result. IMO using array_filter is the preferred method, but the second method might be a little easier to understand for someone new to programming.
Why don't you just try it like this?
foreach($v1 as $k2=>$v2)
{
if($v2!=23)
{
$insert[]=$v2;
}
}
EDIT:
Explanation: You check with the if($v2!=23) if the value of the variable $v2 is not equal to (that is the != sign) any given number that stands after the inequality operator, and if so, it will insert that value to the array $insert.
I hope it is clear now.
Sorry, I've written $v1 instead of $v2, the code should work now.
To add variants :)
$array=array(array(1=>11,2=>22,3=>23,4=>44,5=>55));
$insert=array();
foreach($array as $a)
{
while (($i = array_search(23, $a)) !== false)
{ unset($a[$i]); sort($a); }
$insert[] = $a;
}
print_r($a);
result:
Array ( [0] => Array ( [0] => 11 [1] => 22 [2] => 44 [3] => 55 ) )

Multidimenssion array compare two arrays and update first array value

I want to filter a array by a number and update its status in the first array.
I have two array $arr1,$arr2
$arr1 = array(
0=>array('number'=>100,name=>'john'),
1=>array('number'=>200,name=>'johnny')
);
$arr2= array(
0=>array('number'=>300,name=>'r'),
1=>array('number'=>100,name=>'b'),
2=>array('number'=>200,name=>'c')
);
Final output should be an array like this
$arr1 = array(
0=>array('number'=>100,name=>'b'),
1=>array('number'=>200,name=>'c')
);
Any ideas to start off please ?
For specialized array modifications like this, the method of choice is array walk. It allows you to apply a custom function to each element in a given array.
Now, because of your data format, you will have to do a loop. Wrikken is asking if you can retrieve or transform the data to provide faster access. The algorithm below is O(n^2): it will require as many cycles as there are elements in the first array times the number of elements in the second array, or exactly count($arr1) * count($arr2).
function updateNameFromArray($element, $key, $arr2) {
foreach($arr2 as $value) {
if($value['number'] == $element['number']) {
$element['name'] == $value['name'];
break;
}
}
}
array_walk($arr1, "updateNameFromArray", $arr2);
Now, what Wrikken is suggesting is that if your arrays can be changed to be keyed on the 'number' property instead, then the search/replace operation is much easier. So if this were your data instead:
$arr1 = array(
100=>array('number'=>100,name=>'john'),
200=>array('number'=>200,name=>'johnny')
);
// notice the keys are 100 and 200 instead of 0,1
$arr2= array(
300=>array('number'=>300,name=>'r'),
100=>array('number'=>100,name=>'b'),
200=>array('number'=>200,name=>'c')
);
// notice the keys are 300, 100 and 200 instead of 0,1, 2
Then you could do this in O(n) time, with only looping over the first array.
foreach($arr1 as $key => $value) {
if(isset($arr2[$key])) {
$value['number'] = $arr2[$key]['number'];
}
}
Try this. It's not that clean but i think it would work.
<?php
$arr1 = array(0=>array('number'=>100,'name'=>'john'),1=>array('number'=>200,'name'=>'johnny'));
$arr2= array(0=>array('number'=>300,'name'=>'r'),1=>array('number'=>100,'name'=>'b'),2=>array('number'=>200,'name'=>'c'));
foreach( $arr1 as $key=>$data1 )
{
foreach( $arr2 as $key2=>$data2 )
{
if( $data1['number'] == $data2['number'] )
{
$arr1[$key]['name'] = $arr2[$key2]['name'];
}
}
}
print_r( $arr1 );
?>
the output would be :
Array
(
[0] => Array
(
[number] => 100
[name] => b
)
[1] => Array
(
[number] => 200
[name] => c
)
)
There isn't really a simple way for this to be accomplished with generic PHP functions, so, You might need to create mapping arrays.
The way I would approach this, is creating a loop that goes through the first array, and maps the number value as a key to the index of it's place in $arr1 giving you:
$tmp1 = array();
foreach ($arr1 as $key => $number_name) {
$tmp1[$number_name['number']] = $key;
}
This should give you an array that looks like
$tmp1 [
100 => 0,
200 => 1
];
Then I would loop through the second array, get the number value, if that existed as a key in $tmp1, get the associated value (being the key for $arr1), and use that to update the name in $arr1.
// Loop through $arr2
foreach ($arr2 as $number_name) {
// Get the number value
$number = $number_name['number'];
// Find the $arr1 index
if (isset($tmp1[$number])) {
$arr1_key = $tmp1[$number];
// Set the $arr1 name value
$arr1[$arr1_key]['name'] = $number_name['name'];
}
}
<?php
//Set the arrays
$arr1 = array(
array('number'=>100,'name'=>'john'),
array('number'=>200,'name'=>'johnny')
);
$arr2= array(
array('number'=>300,'name'=>'r'),
array('number'=>100,'name'=>'b'),
array('number'=>200,'name'=>'c')
);
// use a nested for loop to iterate and compare both arrays
for ($i=0;$i<count($arr1);$i++):
for ($j=0;$j<count($arr2);$j++):
if ($arr2[$j]['number']==$arr1[$i]['number'])
$arr1[$i]['name']=$arr2[$j]['name'];
endfor;
endfor;
print_r($arr1);
OUTPUT:
Array (
[0] => Array ( [number] => 100 [name] => b )
[1] => Array ( [number] => 200 [name] => c )
)
That being said, you should probably reconsider the very way your data is structured. Do you really need a multi-dimensional array or can you use a simple associative array, like so:
// set the arrays
$arr1 = array(
'john'=>100,
'johnny'=>200
);
$arr2 = array(
'r'=>300,
'b'=>100,
'c'=>200
);
// find values in arr2 common to both arrays
$arr3 = array_intersect($arr2, $arr1);
// change the key of arr1 to match the corresponding key in arr2
foreach ($arr3 as $key=>$value) {
$old_key = array_search($value, $arr1);
$arr1[$key]=$arr1[$old_key];
unset($arr1[$old_key]);
}
print_r($arr1);
OUTPUT:
Array (
[b] => 100
[c] => 200
)

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