I have an array $num_arr ,so I want get a new array that It's sum is smaller than 10,so i write the code like this,
$num_arr=array(1,3,6,5,4,2,7,9,5,3,6,2,4,7);
$sum=0;
for($i=0;$i<=count($num_arr);$i++){
$sum+=$num_arr[$i];
$k++;
if($sum>=10){
$need_arr[]=array_slice($num_arr,0,$k);
array_splice($num_arr,0, $k);
$k=0;
$sum=0;
}
}
The result $need_arr is not right,that is why and how can get the right array like this: array(array(1,3,6),array(5,4),array(2,7),array(9),...)?
Implemented a "oneliner" just for fun:
$num_arr=array(1,3,6,5,4,2,7,9,5,3,6,2,4,7);
$result = array_reduce($num_arr, function($result, $curr) {
if (!count($result)) {
$result[] = array();
}
$last =& $result[count($result) - 1];
if (array_sum($last) + $curr > 10) {
$result[] = array($curr);
} else {
$last[] = $curr;
}
return $result;
}, array());
var_dump($result);
Online demo: http://ideone.com/aFVmkp
Among other things, you are changing the length of the array when you use array_splice, but you aren't adjusting $i in any way.
In fact, you can remove that array_splice line entirely, since you're continuing to iterate over the array.
Also, you're only starting a new array if you're over 10. You should change your condition to this:
if(!isset($num_arr[$i+1]) || $sum+$num_arr[$i+1] >= 10)
Related
I am trying to manually sort a PHP array without making use of ksort.
This is how my code looks at the moment:
function my_ksort(&$arg){
foreach($arg as $key1 => $value1){
foreach($arg as $key2 => $value2){
if($key1 > $key2){
$aux = $value2;
$arg[$key2] = $value1;
$arg[$key1] = $aux;
}
}
}
}
It doesn't sort, I can't figure out how to make it sort.
You could try this:
function my_ksort(&$arg)
{
$keys=array_keys($arg);
sort($keys);
foreach($keys as $key)
{
$val=$arg[$key];
unset($arg[$key]);
$arg[$key]=$val;
}
}
I'm sorting the keys separately and then deleting the elements one-by-one and appending them to the end, in ascending order.
I'm using another sorting function (sort()), but if you want to eliminate all available sorting functions from your emulation, sort() is much easier to emulate. In fact, #crypticous's algorithm does just that!
This function return array in ASC. Take in consideration that I'm using goto which is supported in (PHP 5 >= 5.3.0)
function ascending_array($array){
if (!is_array($array)){
$array = explode(",", $array);
}
$new = array();
$flag = true;
iter:
$array = array_values($array); // recount array values with new offsets
(isset($min["max"])) ? $min["value"] = $min["max"] : $min["value"] = $array[0];
$min["offset"] = 0;
for ($i=0;$i<count($array);$i++){
if ($array[$i] < $min["value"]){ // redefine min values each time if statement executed
$min["value"] = $array[$i];
$min["offset"] = $i;
}
if ($flag){ // execute only first time
if ($array[$i] > $min["value"]){ // define max value from array
$min["max"] = $array[$i];
}
$flag = false;
}
if ($i === (count($array)-1)){ // last array element
array_push($new,$min["value"]);
unset($array[$min["offset"]]);
}
}
if (count($array)!=0){
goto iter;
}
print_r($new);
}
$arr = array(50,25,98,45);
ascending_array($arr); // 25 45 50 98
PS. When I was studying php, I wrote this function and now remembered that I had it (that's why I really don't remember what I am doing in it, though fact is it's working properly and hopefully there are comments too), hope you'll enjoy :)
DEMO
I was checking some issue related to this post and i wanted to give my insight about it ! here's what i would have done to implement php's sort :
$array_res = array();
$array = array(50,25,98,45);
$i=0;
$temp = $array[0];
$key = array_search($temp, $array);
while ($i<count($array)-1){
$temp = $array[0];
for($n=0;$n<count($array) ;$n++)
{
if($array[$n]< $temp && $array[$n] != -1 )
{
$temp = $array[$n];
}
else{continue;}
}
//get the index for later deletion
$key = array_search($temp, $array);
array_push($array_res, $temp);
/// flag on those which were ordered
$array[$key] =-1;
$i++;
}
// lastly append the highest number
for($n=0;$n<count($array) ;$n++)
{
if ($array[$n] != -1)
array_push($array_res, $array[$n]);
}
// display the results
print_r($array_res);
This code will display : Array
(
[0] => 25
[1] => 45
[2] => 50
[3] => 98
)
Short and sweet
function custom_ksort($arg)
{
$keys = array_keys($arg);
sort($keys);
foreach($keys as $newV)
{
$newArr[$newV] = $arg[$newV];
}
return $newArr;
}
It looks like your issue is that you're changing "temporary" characters $key1 and $key2 but not the actual arrays. You have to change $arg, not just $key1 and $key2.
Try something like:
$arr = Array(3=>"a",7=>"b");
print_r( $arr );
foreach( $arr as $k=>$v ){
unset($arr[$k]);
$arr[$k+1] = $v;
}
print_r($arr);
Hi I need help in removing values from an array using a recursive function
$array = [0] => testing,testing1
[1] => testing,testing1,testing2
[2] => testing,testing1,testing2,testing3
[3] => testing,testing1,testing2,testing3,tesing4
[4] => testing,testing1,testing2,testing3,tesing4
[5] => testing,testing1,testing2,testing3,tesing4
[6] => testing,testing1,testing2,testing3,tesing4
[7] => testing,testing1,testing2,testing3,tesing4
I need to check the array count, ie if count(array[0]) == count(array[1]),then reutrn array
else unset(array[value]);
From the above array I have to remove array[0],[1],[2] and return rest of the array values.
I've tried the below code
$idx =10;
$separtor =',';
function array_delete($idx, $array,$separtor) {
$finalvalue = array();
for ($i = 0; $i < $idx; $i++) {
$values = explode($separtor, $array[$i]);
$valuesnext = explode($separtor, $array[$i+1]);
if(count($values) != count($valuesnext) )
{
unset($array[$i]);
// reset($array);
// array_delete($idx, $array,$separtor);
if (is_array($array)) $array = array_delete($idx, $array,$separtor);
$finalvalue = $array;
}else
{
}
//echo $i;
}
return $finalvalue;
//(is_array($array)) ? array_values($array) : null;
//array_delete($idx, $array,$separtor);
}
I'm getting Notice: Undefined offset: 0 when trying calling recursive, going to infinite loop
Do you want to keep the sub-arrays that have the most items? Your descriptions appear to say this.
If so, something like the following would suffice.
// Get maximum number of items in the arrays
$max_count = max(array_map('count', $array));
// Keep only those arrays having $max_count items
$filtered = array_filter($array, function ($a) use ($max_count) {
return count($a) === $max_count;
});
Aside: if you need the filtered array to have zero-based keys, call array_values() on it.
See an example running online.
If I understand correctly, you want to filter the array such that any value in the final array is of the same length as the last element in the source array. In order to avoid mutating an array while iterating over it, this technique builds a fresh array with the elements that match your criteria.
$matchLength = count($mainArray[count($mainArray) - 1]);
$resultArray = array();
for($i = 0; $i < count($mainArray); $i++) {
if(count($mainArray[$i]) == $matchLength) {
$resultArray[] = $mainArray[$i];
}
}
If you happen to be using PHP 5.3 or greater, you can do this quicker with closures and array_filter:
$matchLength = count($mainArray[count($mainArray) - 1]);
$resultArray = array_filter($mainArray, function($element){return count($element) == $matchLength});
Double check the code, I haven't been writing PHP lately, so this is just an idea.
According to the description you gave, it could be just made (check the count of the current and the provious one, if they don't match, remove the previous one).
Example/Demo:
unset($prevKey);
$count = array();
foreach (array_keys($array) as $key) {
$count[$key] = count($array[$key]);
if (isset($prevKey) && $count[$prevKey] !== $count[$key]) {
unset($array[$prevKey]);
}
$prevKey = $key;
}
If you need to re-iterate to take removals into account, a little goto can do the job Demo:
start:
######
unset($prevKey);
$count = array();
foreach (array_keys($array) as $key) {
$count[$key] = count($array[$key]);
if (isset($prevKey) && $count[$prevKey] !== $count[$key]) {
unset($array[$prevKey]);
goto start;
###########
}
$prevKey = $key;
}
<?php
function filter($fst, $arr){
$new_arr=array();
for($i=0;$i<=(count($arr)-1);$i++){
if(substr($arr[$i], 0, 1) == $fst){
$new_arr[] = $fst;
}
}
return $new_arr;
}
$list = Array("Apparel","Associations","Building/Grounds","Building/Materials",
"Dispensing","Disposables","Distributors");
$new_list[]=filter("A", $list);
for($i=0;$i<=(count($new_list)-1);$i++){
echo '<li>'.$new_list[$i].'</li>';
}
?>
I have created a function named filter() to filter the contents of an array that starts with a character like "a". It does not work at the moment.
First of all I assume that you want to print the word that was OK and not the character you was checking with? $new_arr[] = $fst; should be $new_arr[] = $arr[$i];
Secondly you're adding the resulting array of the function into a new array instead of assigning the array to your variable. $new_list[] = should be $new_list =.
Here's an updated version of your code. I've marked where I've made changes..
function filter($fst, $arr){
$new_arr=array();
for($i=0;$i<=(count($arr)-1);$i++){
if(substr($arr[$i], 0, 1) == $fst){
$new_arr[] = $arr[$i]; <----- Changed here
}
}
return $new_arr;
}
$list = Array("Apparel","Associations","Building/Grounds","Building/Materials",
"Dispensing","Disposables","Distributors");
$new_list=filter("A", $list); <----- And changed here
for($i=0;$i<=(count($new_list)-1);$i++){
echo '<li>'.$new_list[$i].'</li>';
}
Output:
<li>Apparel</li>
<li>Associations</li>
first
don't use
$new_list[] = filter("A", $list);
but simply
$new_list = filter("A", $list);
because your code will try to put an $new_array from filter() into next free index in array variable $new_list
second
$new_arr[] = $fst;
is wrong, because you're setting as new array value the A not matching word. use this instead:
$new_arr[] = $arr[$i];
for($i=0;$i<=(count($arr)-1);$i++){
if(substr($arr[$i], 0, 1) == $fst){
//$new_arr[] = $fst; // <-- Bug is here
$new_arr[] = $arr[$i]; // Try this
}
}
And another bug:
//$new_list[]=filter("A", $list); // This
$new_list = filter("A", $list); // Should be this
foreach($arr as $word) {
// do something with $word
}
reads better than a C-style for $i loop
I have a simple associative array:
$ar = array( 1=>'foo', 2=>'bar', 5=>'foobar', 8=>'barfoo' )
I need to efficiently find holes in the keys. The keys are guaranteed to be integers.
findHole($ar)
> 0
findHole($ar,1)
> 3
findHole($ar,5)
> 6
what is the easiest way to do this?
Try this:
function findHole($array, $key=0) {
while (array_key_exists($key, $array)) {
$key++;
}
return $key;
}
The desired behavior of your findHole function isn't 100% clear to me, but the following code snippet will give you an array that has all the "missing" indexes.
$ar = array( 1=>'foo', 2=>'bar', 5=>'foobar', 8=>'barfoo' );
$keys = array_keys($ar);
$missing_indexes = array_diff(range(0,max($keys)), $keys);
print_r($missing_indexes);
Depending on your use case this may or may not be less efficient. It's using multiple function calls and arrays are passed around by value by default, but those functions are operating at native code speeds, while solutions using loops are going to be running at PHP speed.
Use case, benchmark, etc.
All holes:
function GetHoles($arr)
{
$holes = array();
$max_value = max(array_keys($arr));
for($i = 0; $i < $max_value; $i++)
{
if(!in_array($i, $keys)) $holes[] = $i;
}
return $holes;
}
if you just want to condense the array, try this:
function FlattenArray( $o )
{
$res = array();
foreach($o as $v)
{
$res = array_merge($res, FlattenArray($v));
}
return $res;
}
What is the most efficient way to check if an array is a flat array
of primitive values or if it is a multidimensional array?
Is there any way to do this without actually looping through an
array and running is_array() on each of its elements?
Use count() twice; one time in default mode and one time in recursive mode. If the values match, the array is not multidimensional, as a multidimensional array would have a higher recursive count.
if (count($array) == count($array, COUNT_RECURSIVE))
{
echo 'array is not multidimensional';
}
else
{
echo 'array is multidimensional';
}
This option second value mode was added in PHP 4.2.0. From the PHP Docs:
If the optional mode parameter is set to COUNT_RECURSIVE (or 1), count() will recursively count the array. This is particularly useful for counting all the elements of a multidimensional array. count() does not detect infinite recursion.
However this method does not detect array(array()).
The short answer is no you can't do it without at least looping implicitly if the 'second dimension' could be anywhere. If it has to be in the first item, you'd just do
is_array($arr[0]);
But, the most efficient general way I could find is to use a foreach loop on the array, shortcircuiting whenever a hit is found (at least the implicit loop is better than the straight for()):
$ more multi.php
<?php
$a = array(1 => 'a',2 => 'b',3 => array(1,2,3));
$b = array(1 => 'a',2 => 'b');
$c = array(1 => 'a',2 => 'b','foo' => array(1,array(2)));
function is_multi($a) {
$rv = array_filter($a,'is_array');
if(count($rv)>0) return true;
return false;
}
function is_multi2($a) {
foreach ($a as $v) {
if (is_array($v)) return true;
}
return false;
}
function is_multi3($a) {
$c = count($a);
for ($i=0;$i<$c;$i++) {
if (is_array($a[$i])) return true;
}
return false;
}
$iters = 500000;
$time = microtime(true);
for ($i = 0; $i < $iters; $i++) {
is_multi($a);
is_multi($b);
is_multi($c);
}
$end = microtime(true);
echo "is_multi took ".($end-$time)." seconds in $iters times\n";
$time = microtime(true);
for ($i = 0; $i < $iters; $i++) {
is_multi2($a);
is_multi2($b);
is_multi2($c);
}
$end = microtime(true);
echo "is_multi2 took ".($end-$time)." seconds in $iters times\n";
$time = microtime(true);
for ($i = 0; $i < $iters; $i++) {
is_multi3($a);
is_multi3($b);
is_multi3($c);
}
$end = microtime(true);
echo "is_multi3 took ".($end-$time)." seconds in $iters times\n";
?>
$ php multi.php
is_multi took 7.53565130424 seconds in 500000 times
is_multi2 took 4.56964588165 seconds in 500000 times
is_multi3 took 9.01706600189 seconds in 500000 times
Implicit looping, but we can't shortcircuit as soon as a match is found...
$ more multi.php
<?php
$a = array(1 => 'a',2 => 'b',3 => array(1,2,3));
$b = array(1 => 'a',2 => 'b');
function is_multi($a) {
$rv = array_filter($a,'is_array');
if(count($rv)>0) return true;
return false;
}
var_dump(is_multi($a));
var_dump(is_multi($b));
?>
$ php multi.php
bool(true)
bool(false)
For PHP 4.2.0 or newer:
function is_multi($array) {
return (count($array) != count($array, 1));
}
I think this is the most straight forward way and it's state-of-the-art:
function is_multidimensional(array $array) {
return count($array) !== count($array, COUNT_RECURSIVE);
}
After PHP 7 you could simply do:
public function is_multi(array $array):bool
{
return is_array($array[array_key_first($array)]);
}
You could look check is_array() on the first element, under the assumption that if the first element of an array is an array, then the rest of them are too.
I think you will find that this function is the simplest, most efficient, and fastest way.
function isMultiArray($a){
foreach($a as $v) if(is_array($v)) return TRUE;
return FALSE;
}
You can test it like this:
$a = array(1 => 'a',2 => 'b',3 => array(1,2,3));
$b = array(1 => 'a',2 => 'b');
echo isMultiArray($a) ? 'is multi':'is not multi';
echo '<br />';
echo isMultiArray($b) ? 'is multi':'is not multi';
Don't use COUNT_RECURSIVE
click this site for know why
use rsort and then use isset
function is_multi_array( $arr ) {
rsort( $arr );
return isset( $arr[0] ) && is_array( $arr[0] );
}
//Usage
var_dump( is_multi_array( $some_array ) );
Even this works
is_array(current($array));
If false its a single dimension array if true its a multi dimension array.
current will give you the first element of your array and check if the first element is an array or not by is_array function.
You can also do a simple check like this:
$array = array('yo'=>'dream', 'mydear'=> array('anotherYo'=>'dream'));
$array1 = array('yo'=>'dream', 'mydear'=> 'not_array');
function is_multi_dimensional($array){
$flag = 0;
while(list($k,$value)=each($array)){
if(is_array($value))
$flag = 1;
}
return $flag;
}
echo is_multi_dimensional($array); // returns 1
echo is_multi_dimensional($array1); // returns 0
I think this one is classy (props to another user I don't know his username):
static public function isMulti($array)
{
$result = array_unique(array_map("gettype",$array));
return count($result) == 1 && array_shift($result) == "array";
}
In my case. I stuck in vary strange condition.
1st case = array("data"=> "name");
2nd case = array("data"=> array("name"=>"username","fname"=>"fname"));
But if data has array instead of value then sizeof() or count() function not work for this condition. Then i create custom function to check.
If first index of array have value then it return "only value"
But if index have array instead of value then it return "has array"
I use this way
function is_multi($a) {
foreach ($a as $v) {
if (is_array($v))
{
return "has array";
break;
}
break;
}
return 'only value';
}
Special thanks to Vinko Vrsalovic
Its as simple as
$isMulti = !empty(array_filter($array, function($e) {
return is_array($e);
}));
This function will return int number of array dimensions (stolen from here).
function countdim($array)
{
if (is_array(reset($array)))
$return = countdim(reset($array)) + 1;
else
$return = 1;
return $return;
}
Try as follows
if (count($arrayList) != count($arrayList, COUNT_RECURSIVE))
{
echo 'arrayList is multidimensional';
}else{
echo 'arrayList is no multidimensional';
}
$is_multi_array = array_reduce(array_keys($arr), function ($carry, $key) use ($arr) { return $carry && is_array($arr[$key]); }, true);
Here is a nice one liner. It iterates over every key to check if the value at that key is an array. This will ensure true