PHP Count values of an array - php

Is there a way to count the values of a multidimensional array()?
$families = array
(
"Test"=>array
(
"test1",
"test2",
"test3"
)
);
So for instance, I'd want to count the 3 values within the array "Test"... ('test1', 'test2', 'test3')?

$families = array
(
"Test"=>array
(
"test1",
"test2",
"test3"
)
);
echo count($families["Test"]);

I think I've just come up with a rather different way of counting the elements of an (unlimited) MD array.
<?php
$array = array("ab", "cd", array("ef", "gh", array("ij")), "kl");
$i = 0;
array_walk_recursive($array, function() { global $i; return ++$i; });
echo $i;
?>
Perhaps not the most economical way of doing the count, but it seems to work! You could, inside the anonymous function, only add the element to the counted total if it had a non empty value, for example, if you wanted to extend the functionality. An example of something similar could be seen here:
<?php
$array = array("ab", "cd", array("ef", "gh", array("ij")), "kl");
$i = 0;
array_walk_recursive($array, function($value, $key) { global $i; if ($value == 'gh') ++$i; });
echo $i;
?>

The count method must get you there. Depending on what your actual problem is you maybe need to write some (recursive) loop to sum all items.

A static array:
echo 'Test has ' . count($families['test']) . ' family members';
If you don't know how long your array is going to be:
foreach($families as $familyName => $familyMembers)
{
echo $familyName . ' has got ' . count($familyMembers) . ' family members.';
}

function countArrayValues($ar, $count_arrays = false) {
$cnt = 0;
foreach ($ar as $key => $val) {
if (is_array($ar[$key])) {
if ($count_arrays)
$cnt++;
$cnt += countArrayValues($ar);
}
else
$cnt++;
}
return $cnt;
}
this is custom function written by me, just pass an array and you will get full count of values. This method wont count elements which are arrays if you pass second parameter as false, or you don't pass anything. Pass tru if you want to count them also.
$count = countArrayValues($your_array);

Related

I want to know the correct syntax of declaring multiple variables in php with small changes like mentioned below

$str='abcde';//for sub-question numbers
for ($i=1; $i <=10 ; $i++) {//i loop is for question numbers 1 to 10
for ($j=0; $j<5 ; $j++) {//j loop is for sub-questions from a to e
$q{$i}{$str[$j]}=$_POST['q{$i}{$str[j]}'];//not sure about this part
}
}
Here the main idea is to create 50 variables from q1a,q1b,... till q10d,q10e.
I'm not 100% clear on what the values of those variables will be, but here is how to create an array with those variable names in them.
$questions = array(1,2,3,4,5,6,7,8,9,10); //questions
$subQuestions = array('a','b','c','d','e'); //sub-question
$allQuestions = array();
foreach($questions as $question) {//loop the questions
foreach($subQuestions as $subQ) {//loop the sub questions
// I'm not clear what you're trying to do here -> $q{$i}{$str[$j]}=$_POST['q{$i}{$str[j]}'];//not sure about this part
$allQuestions["q" . $question . $subQ] = "I'm an empty value right now"; //what value goes here?
}
}
var_dump($allQuestions);
You can do something like this
$values = array("q1a", "q1b", "q1c", "q1d", "q1e", "q2a", "q2b", "q2c", "q2d", "q2e");
for($i=;$i<$sizeof($values);$i++)
{
$values[$i] = $_POST['q{$i}{$str[j]}'];
}
If all your POST vars which you want to grab are prepended with q then just filter them with array_filter().
Then you can use extract(), but tbh, you should just use the array.
<?php
$_POST = [
'q1' => 'baz',
'foo' => 'bar',
];
$q = array_filter($_POST, function($k) {
return substr($k, 0, 1) === 'q';
}, ARRAY_FILTER_USE_KEY);
extract($q);
// filtered array
print_r($q);
// extract'ed
echo $q1;
Result:
Array
(
[q1] => baz
)
baz
https://3v4l.org/rvMR6

Count occurrences of a specific value in multidimensional array

Let's say I have a multidimensional array like this:
[
["Thing1", "OtherThing1"],
["Thing1", "OtherThing2"],
["Thing2", "OtherThing3"]
]
How would I be able to count how many times the value "Thing1" occurs in the multidimensional array?
you can use array_search for more information see this http://www.php.net/manual/en/function.array-search.php
this code is sample of this that is in php document sample
<?php
function recursiveArraySearchAll($haystack, $needle, $index = null)
{
$aIt = new RecursiveArrayIterator($haystack);
$it = new RecursiveIteratorIterator($aIt);
$resultkeys;
while($it->valid()) {
if (((isset($index) AND ($it->key() == $index)) OR (!isset($index))) AND (strpos($it->current(), $needle)!==false)) { //$it->current() == $needle
$resultkeys[]=$aIt->key(); //return $aIt->key();
}
$it->next();
}
return $resultkeys; // return all finding in an array
} ;
?>
If needle is found in haystack more than once, the first matching key is returned. To return the keys for all matching values, use array_keys() with the optional search_value parameter instead.
http://www.php.net/manual/en/function.array-keys.php
Try this :
$arr =array(
array("Thing1","OtherThing1"),
array("Thing1","OtherThing2"),
array("Thing2","OtherThing3")
);
echo "<pre>";
$res = array_count_values(call_user_func_array('array_merge', $arr));
echo $res['Thing1'];
Output :
Array
(
[Thing1] => 2
[OtherThing1] => 1
[OtherThing2] => 1
[Thing2] => 1
[OtherThing3] => 1
)
It gives the occurrence of each value. ie : Thing1 occurs 2 times.
EDIT : As per OP's comment : "Which array do you mean resulting array?" - The input array. So for example this would be the input array: array(array(1,1),array(2,1),array(3,2)) , I only want it to count the first values (1,2,3) not the second values (1,1,2) – gdscei 7 mins ago
$arr =array(
array("Thing1","OtherThing1"),
array("Thing1","OtherThing2"),
array("Thing2","OtherThing3")
);
$res = array_count_values(array_map(function($a){return $a[0];}, $arr));
echo $res['Thing1'];
function showCount($arr, $needle, $count=0)
{
// Check if $arr is array. Thx to Waygood
if(!is_array($arr)) return false;
foreach($arr as $k=>$v)
{
// if item is array do recursion
if(is_array($v))
{
$count = showCount($v, $needle, $count);
}
elseif($v == $needle){
$count++;
}
}
return $count;
}
Using in_array can help:
$cont = 0;
//for each array inside the multidimensional one
foreach($multidimensional as $m){
if(in_array('Thing1', $m)){
$cont++;
}
}
echo $cont;
For more info: http://php.net/manual/en/function.in-array.php
try this
$arr =array(
array("Thing1","OtherThing1"),
array("Thing1","OtherThing2"),
array("Thing2","OtherThing3")
);
$abc=array_count_values(call_user_func_array('array_merge', $arr));
echo $abc[Thing1];
$count = 0;
foreach($array as $key => $value)
{
if(in_array("Thing1", $value)) $count++;
}
If you prefer code brevity zero global scope pollution, you can count every value and access the one count that you do want:
echo array_count_values(array_merge(...$array))['Thing1'] ?? 0;
If you don't want to bother counting values where the count will never be needed, then you can visit leafnodes with array_walk_recursive() and +1 everytime the target value is encountered.
$thing1Count = 0;
array_walk_recursive($array, function($v) use(&$thing1Count) { $thing1Count += ($v === 'Thing1'); });
echo $thing1Count;
Both snippets return 2. Here's a Demo.

Reverse order of foreach list items

I would like to reverse the order of this code's list items. Basically it's a set of years going from oldest to recent and I am trying to reverse that output.
<?php
$j=1;
foreach ( $skills_nav as $skill ) {
$a = '<li><a href="#" data-filter=".'.$skill->slug.'">';
$a .= $skill->name;
$a .= '</a></li>';
echo $a;
echo "\n";
$j++;
}
?>
Walking Backwards
If you're looking for a purely PHP solution, you can also simply count backwards through the list, access it front-to-back:
$accounts = Array(
'#jonathansampson',
'#f12devtools',
'#ieanswers'
);
$index = count($accounts);
while($index) {
echo sprintf("<li>%s</li>", $accounts[--$index]);
}
The above sets $index to the total number of elements, and then begins accessing them back-to-front, reducing the index value for the next iteration.
Reversing the Array
You could also leverage the array_reverse function to invert the values of your array, allowing you to access them in reverse order:
$accounts = Array(
'#jonathansampson',
'#f12devtools',
'#ieanswers'
);
foreach ( array_reverse($accounts) as $account ) {
echo sprintf("<li>%s</li>", $account);
}
Or you could use the array_reverse function.
array_reverse() does not alter the source array, but returns a new array. (See array_reverse().) So you either need to store the new array first or just use function within the declaration of your for loop.
<?php
$input = array('a', 'b', 'c');
foreach (array_reverse($input) as $value) {
echo $value."\n";
}
?>
The output will be:
c
b
a
So, to address to OP, the code becomes:
<?php
$j=1;
foreach ( array_reverse($skills_nav) as $skill ) {
$a = '<li><a href="#" data-filter=".'.$skill->slug.'">';
$a .= $skill->name;
$a .= '</a></li>';
echo $a;
echo "\n";
$j++;
}
Lastly, I'm going to guess that the $j was either a counter used in an initial attempt to get a reverse walk of $skills_nav, or a way to count the $skills_nav array. If the former, it should be removed now that you have the correct solution. If the latter, it can be replaced, outside of the loop, with a $j = count($skills_nav).
If you don't mind destroying the array (or a temp copy of it) you can do:
$stack = array("orange", "banana", "apple", "raspberry");
while ($fruit = array_pop($stack)){
echo $fruit . "\n<br>";
}
produces:
raspberry
apple
banana
orange
I think this solution reads cleaner than fiddling with an index and you are less likely to introduce index handling mistakes, but the problem with it is that your code will likely take slightly longer to run if you have to create a temporary copy of the array first.
Fiddling with an index is likely to run faster, and it may also come in handy if you actually need to reference the index, as in:
$stack = array("orange", "banana", "apple", "raspberry");
$index = count($stack) - 1;
while($index > -1){
echo $stack[$index] ." is in position ". $index . "\n<br>";
$index--;
}
But as you can see, you have to be very careful with the index...
You can use usort function to create own sorting rules
Assuming you just need to reverse an indexed array (not associative or multidimensional) a simple for loop would suffice:
$fruits = ['bananas', 'apples', 'pears'];
for($i = count($fruits)-1; $i >= 0; $i--) {
echo $fruits[$i] . '<br>';
}
If your array is populated through an SQL Query consider reversing the result in MySQL, ie :
SELECT * FROM model_input order by creation_date desc
If you do not have Boolean false values in your array, you could use next code based on internal pointer functions:
$array = ['banana', 'apple', 'pineapple', 'lemon'];
$value = end($array);
while ($value !== false) {
// In case you need a key
$key = key($array);
// Do something you need to
echo $key . ' => ' . $value . "\n";
// Move pointer
$value = prev($array);
}
This solution works for associative arrays with arbitrary keys and do not require altering existing or creating a new one.
<?php
$j=1;
array_reverse($skills_nav);
foreach ( $skills_nav as $skill ) {
$a = '<li><a href="#" data-filter=".'.$skill->slug.'">';
$a .= $skill->name;
$a .= '</a></li>';
echo $a;
echo "\n";
$j++;
}
?>

associative array pointers / traversing associative array

Does next() and prev() work on associative arrays?
I'm trying to traverse through a dataset that uses two records to describe one "game" if you will. So when I'm on the second record w/ matching id i need to look at the record before and grab eg_item['final_score'].
{"id":"75", "team_name":"TEAM1", "home_team_name":"TEAM1", "image":"TEAM1_HOME.png", "final_score":"37"},
{"id":"75", "team_name":"TEAM2", "home_team_name":"TEAM2", "image":"TEAM2_AWAY.png", "final_score":"10"},
{"id":"76", "team_name":"TEAM1", "home_team_name":"TEAM1", "image":"TEAM1_HOME.png", "final_score":"10"},
{"id":"76", "team_name":"TEAM2", "home_team_name":"TEAM2", "image":"TEAM2_AWAY.png", "final_score":"14"},
All of the examples I'm finding use lame array('one','two',three') type examples that just don't help.
code sample:
foreach( $json_output as $eg_item ) :
if( $this_game_id == $last_game_id ) :
// get this records info
$b_score = $eg_item['final_score'];
$b_team_name = $eg_item['team_name'];
prev( $json_output );
// get previous records info
$a_score = $eg_item['final_score'];
$a_team_name = $eg_item['team_name'];
$a_game_id = $eg_item['id'];
// put pointer back
next( $json_output );
else :
// skip next record
endif;
endforeach;
That looks like an array of associative arrays, right? If so, loop through them by index 2 at a time, then you can look at the current inner array and the previous inner array in each iteration of the loop:
for ($i = 1; $i < count($array); $i+= 2) {
$current = $array[$i];
$last = $array[$i-1];
//$current['final_score'], $last['final_score'], etc
}
Yes they work just fine, heres a small test case i have done:
<?php
$sample = array(
"first" => Array("a","d","c"),
"second" => Array("a","d","c"),
"third" => Array("a","d","c"),
"fourth" => Array("a","d","c")
);
while(next($sample))
{
$item = current($sample);
echo key($sample) . "\n";
if(is_array($item))
{
echo "\t" . current($item) . "\n";
while(next($item))
{
echo "\t" . current($item) . "\n";
}
}
}
?>
output: http://codepad.org/2ZeqzWcx

Count number of values in array with a given value

Say I have an array like this:
$array = array('', '', 'other', '', 'other');
How can I count the number with a given value (in the example blank)?
And do it efficiently? (for about a dozen arrays with hundreds of elements each)
This example times out (over 30 sec):
function without($array) {
$counter = 0;
for($i = 0, $e = count($array); $i < $e; $i++) {
if(empty($array[$i])) {
$counter += 1;
}
}
return $counter;
}
In this case the number of blank elements is 3.
How about using array_count _values to get an array with everything counted for you?
Just an idea, you could use array_keys( $myArray, "" ) using the optional second parameter which specifies a search-value. Then count the result.
$myArray = array( "","","other","","other" );
$length = count( array_keys( $myArray, "" ));
I dont know if this would be faster but it's something to try:
$counter = 0;
foreach($array as $value)
{
if($value === '')
$counter++;
}
echo $counter;
You could also try array_reduce, with a function which would just count the value you are interested in. eg
function is_empty( $v, $w )
{ return empty( $w ) ? ($v + 1) : $v; }
array_reduce( $array, 'is_empty', 0 );
Some benchmarking might tell you if this is faster than array_count_values()
We use array_filter function to find out number of values in array
$array=array('','','other','','other');
$filled_array=array_filter($array);// will return only filled values
$count=count($filled_array);
echo $count;// returns array count
Generally for counting blanks only.
Really depends on use case and speed needed. Personally I like doing things one one line.
Like the chosen response though But you still need a line to extract the data needed though to another variable.
$r = count($x) - count(array_filter($x));
function arrayvaluecount($array) {
$counter = 0;
foreach($array as $val){
list($v)=$val;
if($v){
$counter =$counter+1;
}
}
return $counter;
}
function countarray($array)
{ $count=count($array);
return $count;
}
$test=$array = array('', '', 'other', '', 'other');
echo countarray($test);

Categories