I have an array like this:
<?php
$arr = [
'a' => [
'a1' => [
'A11', 'A12', 'A13'
]
]
];
I can change the A13 element in an easy way:
$arr['a']['a1'][2] = 'A13 NEW';
But I want to do this with a function, something like this:
f($arr, ['a', 'a1', 2], 'A13 New');
I write this function using eval and I don't like it.
<?php
function f(&$array, $index, $value) {
$e = '$array';
for ($i = 0, $l = count($index); $i < $l; $i++) {
$e .= '[$index[' . $i . ']]';
}
$e .= ' = $value;';
// now we have `$e` like this
// $array[$index[0]][$index[1]][$index[2]] = $value;
eval($e);
}
How can I write this function without using eval?
$arr = array(
'a' => array(
'a1' => array(
'A11', 'A12', 'A13'
)
)
);
function f(&$arr, $index, $value) {
$tmp = &$arr;
foreach ($index as $key) {
$tmp = &$tmp[$key];
}
$tmp = $value;
}
f($arr, array('a', 'a1', 2), 'A13 New');
//$arr['a']['a1'][2] = 'A13 NEW';
var_dump($arr);
if ( $_GET['_value'] == 'moto' )
{
$array[] = array('1' => 'Yamaha');
$array[] = array('2' => 'Suzuki');
$array[] = array('3' => 'Triumph');
$array[] = array('4' => 'KTM');
$array[] = array('5' => 'Honda');
$array[] = array('6' => 'Harley Davidson');
$array[] = array('7' => 'Buell');
$array[] = array('8' => 'MV Agusta');
$array[] = array('9' => 'Ducati');
$array[] = array('10' => 'Other');
}
$array = sort($array);
echo json_encode( $array );
that is the code i have and its pulled by a chained dropdown.
I want it to return the values sorted alphabetically but based on the code you see it returns an empty array. what could be the mistake I am making /
Your code fails because you have an array of arrays here.
You should either search for "sort php array by sub-array key"
Or you can try something like:
$array[1] = 'Yamaha';
$array[2] = 'Suzuki';
// ...
sort($array);
echo json_encode($array);
Your array contains arrays, hence cannot be sorted, try:
$array[1] = 'Yamaha';
$array[2] = 'Suzuki';
then sort($array)
You can use uasort() function
like:
function cmp($a, $b) {
$a = reset($a);
$b = reset($b);
if ($a == $b) {
return 0;
}
return ($a < $b) ? -1 : 1;
}
uasort($array, 'cmp')
It's not at all pretty but this does the job.
Unless you're constrained otherwise you should really use some of the other suggestions.
<?
if ( $_GET['_value'] == 'moto' ) {
$array[] = array('1' => 'Yamaha');
$array[] = array('2' => 'Suzuki');
$array[] = array('3' => 'Triumph');
$array[] = array('4' => 'KTM');
$array[] = array('5' => 'Honda');
$array[] = array('6' => 'Harley Davidson');
$array[] = array('7' => 'Buell');
$array[] = array('8' => 'MV Agusta');
$array[] = array('9' => 'Ducati');
$array[] = array('10' => 'Other');
foreach($array as $i => $v)
{
$v = array_values($v);
$sort[] = $v[0];
}
sort($sort);
$c = 0;
foreach($sort as $i => $v)
{
$c++;
$sorted[] = array($c=>$v);
}
echo json_encode($sorted);
}
?>
I need to get two arrays to merge into one while keeping all the keys in place and listing the values in an array like in this example:
$array1 = array('car' => '3', 'bus' => '2');
$array2 = array('dog' => '1', 'car' => '2', 'bird' => '9');
$merged = array(
'car' => array('3','2'),
'bus' => array('2',null),
'dog' => array(null,'1'),
'bird' => (null,'9')
);
function merge_common_keys(){
$arr = func_get_args();
$num = func_num_args();
$keys = array();
$i = 0;
for ($i=0; $i<$num; ++$i){
$keys = array_merge($keys, array_keys($arr[$i]));
}
$keys = array_unique($keys);
$merged = array();
foreach ($keys as $key){
$merged[$key] = array();
for($i=0; $i<$num; ++$i){
$merged[$key][] = isset($arr[$i][$key]) ? $arr[$i][$key] : null;
}
}
return $merged;
}
Usage:
$merged = merge_common_keys($array1,$array2);
PS. It can work with more than two arrays, just pass as many as you want as next arguments.
Something like this? http://php.net/array_merge_recursive
Out of this:
$arr = array(
array('boo', 4),
array('boo', 1),
array('foo', 2),
array('foo', 6)
);
how best calculate into this?:
$arr = array(
'boo' => 5,
'foo' => 8
);
$sum = array();
for ( $i = 0; $i < count( $arr ); $i++ )
{
if ( !isset( $sum[ $arr[$i][0] ] )
$sum[ $arr[$i][0] ] = 0;
$sum[ $arr[$i][0] ] += $arr[$i][1];
}
print_r( $sum );
$arr = array(
array('boo', 4),
array('boo', 1),
array('foo', 2),
array('foo', 6)
);
Then:
$arr2 = array();
foreach($arr as $value) {
if(isSet($arr2[$value[0]])) $arr2[$value[0]] += $value[1];
else $arr2[$value[0]] = $value[1];
}
I would like to check if my array has any duplicates and return the duplicated values in an array.
I want this to be as efficient as possible.
Example:
$array = array( 1, 2, 2, 4, 5 );
function return_dup($array); // should return 2
$array2 = array( 1, 2, 1, 2, 5 );
function return_dup($array2); // should return an array with 1,2
Also the initial array is always 5 positions long
this will be ~100 times faster than array_diff
$dups = array();
foreach(array_count_values($arr) as $val => $c)
if($c > 1) $dups[] = $val;
You can get the difference of the original array and a copy without duplicates using array_unique and array_diff_assoc:
array_diff_assoc($arr, array_unique($arr))
function array_dup($ar){
return array_unique(array_diff_assoc($ar,array_unique($ar)));
}
Should do the trick.
You can do like this:
function showDups($array)
{
$array_temp = array();
foreach($array as $val)
{
if (!in_array($val, $array_temp))
{
$array_temp[] = $val;
}
else
{
echo 'duplicate = ' . $val . '<br />';
}
}
}
$array = array(1,2,2,4,5);
showDups($array);
Output:
duplicate = 2
function returndup($array)
{
$results = array();
$duplicates = array();
foreach ($array as $item) {
if (in_array($item, $results)) {
$duplicates[] = $item;
}
$results[] = $item;
}
return $duplicates;
}
in addition to gumbo's answer:
function returndup($arr)
{
return array_diff_key($arr, array_unique($arr));
}
I did some tests and indeed #user187291's variant is the fastest. But, it turns out that #Gumbo's and #faebser's alternative are almost as fast, #faebser's being just slightly faster than #Gumbo's and sometimes even fastest of all.
Here's the code I used
$array = array(1, "hello", 1, "world", "hello");
$times = 1000000;
$start = microtime(true);
for ($i = 0; $i < $times; $i++) {
$dups = array();
foreach(array_count_values($array) as $val => $c)
if( $c > 1) $dups[] = $val;
}
$end = microtime(true);
echo 'variant 1 (user187291): ' . ($end - $start);
echo '<br><br><br>';
$start = microtime(true);
for ($i = 0; $i < $times; $i++)
$dups = array_unique(array_diff_assoc($array, array_unique($array)));
$end = microtime(true);
echo 'variant 2 (JAL): ' . ($end - $start);
echo '<br><br><br>';
$start = microtime(true);
for ($i = 0; $i < $times; $i++)
$dups = array_diff_assoc($array, array_unique($array));
$end = microtime(true);
echo 'variant 3 (Gumbo): ' . ($end - $start);
echo '<br><br><br>';
$start = microtime(true);
for ($i = 0; $i < $times; $i++)
$dups = array_diff_key($array, array_unique($array));
$end = microtime(true);
echo 'variant 4 (faebser): ' . ($end - $start);
echo '<br><br><br>';
I have found another way to return duplicates in an array
function printRepeating($arr, $size)
{
$i;
$j;
for($i = 0; $i < $size; $i++)
for($j = $i + 1; $j < $size; $j++)
if($arr[$i] == $arr[$j])
echo $arr[$i], " ";
}
printRepeating($array, sizeof($array,0);
If you need a solution that will work with an array of arrays (or any array values other than integers or strings) try this:
function return_dup( $arr ) {
$dups = array();
$temp = $arr;
foreach ( $arr as $key => $item ) {
unset( $temp[$key] );
if ( in_array( $item, $temp ) ) {
$dups[] = $item;
}
}
return $dups;
}
$arr = array(
array(
0 => 'A',
1 => 'B',
),
array(
0 => 'A',
1 => 'B',
),
array(
0 => 'C',
1 => 'D',
),
array(
0 => 'C',
1 => 'D',
),
array(
0 => 'E',
1 => 'F',
),
array(
0 => 'F',
1 => 'E',
),
array(
0 => 'Y',
1 => 'Z',
),
);
var_export( return_dup( $arr ) );
/*
array (
0 => array (
0 => 'A',
1 => 'B',
),
1 => array (
0 => 'C',
1 => 'D',
),
)
*/
As per your problem if you have duplicate values then you have to return those values. I write a function for this problem. If your array has duplicate values this function returns these values within the array otherwise it returns null values. Here is an example:
function containsDuplicate($array_values) {
$duplicates_values = [];
for($i = 0; $i < count($array_values); $i++){
for ($j=$i+1; $j <count($array_values) ; $j++) {
if ($array_values[$i] == $array_values[$j]) {
$duplicates_values[] = $array_values[$i];
}
}
}
if(count($duplicates_values) > 0){
return $duplicates_values;
}
}
$duplicate_array = array();
for($i=0;$i<count($array);$i++){
for($j=0;$j<count($array);$j++){
if($i != $j && $array[$i] == $array[$j]){
if(!in_array($array[$j], $duplicate_array)){
$duplicate_array[] = $array[$j];
}
}
}
}