How to prevent duplicate keys from array_push - php

I have 2 2D arrays, how can i get the unique keys and only push those? For example:
$array = json_decode('[{"7654321":1368356071},{"1234567":1368356071}]',true);
$array2 = array(array(1234567 => time()), array(7654321 => time()), array(2345678 => time()));
//array_push($array, $array2[2]);
-- How can I dynamically get the unique key like $array2[2] in this example?

why not to use array_unique() function in php? http://php.net/manual/ru/function.array-unique.php

You mean, you would like to push into another array (let's say in $keys_unique) whatever key(s) that are present only in one of the first two arrays, but not present in both of them?
Try this:
$arrays_mixed = array( //your $array and $array2; you can put as many arrays as you want here
json_decode('[{"7654321":1368356071},{"1234567":1368356071}]',true)
,array(array(1234567 => time()), array(7654321 => time()), array(2345678 => time()))
);
//begin getting all keys
$arrays_keys = array(); //will hold all keys from arrays_mixed
$keys_unique = array(); //will hold all unique keys out of arrays_key
for($x=0;$x<count($arrays_mixed);$x++){
$arrays_keys[$x] = array(); //prepares a "keys holder"
$toflatten = $arrays_mixed[$x];
$c1 = 0;
do{
$arrmixed = array();
$arrclean = array();
foreach($toflatten as $a){
$arrmixed = $this->keys_finder($a,1);
$arrclean[$c1] = $this->keys_finder($a,2);
$c1++;
}
$toflatten = $arrmixed;
}while(is_array($toflatten));
for($c2=0;$c2<$c1;$c2++)
foreach($arrclean[$c2] as $ac)
array_push($arrays_keys[$x],$ac);
}//end geting all keys
//begin finding unique keys
foreach($arrays_keys as $ak)
foreach($ak as $add)
$keys_unique = $this->unique_inserter($arrays_keys,$keys_unique,$add);
//end finding unique keys
Here are the functions you need
function unique_inserter($arrays_keys,$keys_unique,$add){
$detector = 0; //detects how many arrays contain a value
foreach($arrays_keys as $ak)
if(in_array($add,$ak))
$detector++;
if($detector<2) //if value is found in one array only
array_push($keys_unique,$add);
return $keys_unique;
}
function keys_finder($array,$return){
$arrmixed = array();
$arrclean = array();
foreach($array as $key=>$a)
if(is_array($a))
foreach($a as $aa)
array_push($arrmixed,$aa);
else
array_push($arrclean,$key);
switch($return){
case 1:
return (count($arrmixed)==0)?'':$arrmixed;
break;
case 2:
return $arrclean;
break;
}
}
I have tested this code and it works on my side. Hope it helps.

Related

PHP array comparision error

I have 2 SELECT statement in my PHP. Both the select statements fetch data from two different DB. The fetched data is saved in PDO Assoc Array. The problem is when I want to compare those two arrays to find that if the column 'id' exist in both arrays or not. If it exists then ignore it. If it's a unique id then save it into a third array. But I found some problems in my Logic Below
And after running the below code I am getting a couple of error:
1: Array to string conversion
2: duplicate key value violates unique constraint
$arr1 = $msql->fetchAll(PDO::FETCH_ASSOC);
$array1 = array();
foreach($arr1 as $x){
$array1[] = $x['id'];
}
$arr2 = $psql->fetechAll(PDO::FETCH_ASSOC);
$array2 = array();
foreach($arr2 as $y){
$array2[] = $y['id'];
}
$finalarray = array();
for ($i = 0; $i < count($arr1); $i++){
if(count(array_intersect($array1,$array2)) <= 1){// is the count of id is 1 or less save that whole row in the $finalarray
$finalarray = $arr1[$i]; // saving the unique row.
}
else{
continue;
}
}
All I am trying to get the unique row of data array() after comparing their id column.
You can use in_array() function as both arrays are index array.
$finalarray = array();
for ($i = 0; $i < count($arr1); $i++){
if(count(array_intersect($array1,$array2)) <= 1){// is the count of id is 1 or less save that whole row in the $finalarray
$finalarray = $arr1[$i]; // saving the unique row.
}
else{
continue;
}
}
make change in code:
$finalarray = array();
for ($i = 0; $i < count($arr1); $i++){
if(!in_array($array1[$i], $array2)){
$finalarray[] = $array1[$i]; // saving the unique row.
}
}
You can simply use array_intersect() to get common values between two array. for difference, can use array_diff()
$array1 = [1,2,3,4,5,6,7];
$array2 = [2,4,6];
//array_intersect — Computes the intersection of arrays
$result = array_intersect($array1, $array2);
print_r($result);
//array_diff — Computes the difference of arrays
$result = array_diff($array1, $array2);
print_r($result);
DEMO
Rather than using 3 different arrays to get unique ids, you can do it by using one array. Make changes to your code as below:
$finalarray = array();
$arr1 = $msql->fetchAll(PDO::FETCH_ASSOC);
foreach($arr1 as $x){
if (!in_array($x['id'],$finalarray)) { // check id is already stored or not
$finalarray[] = $x['id'];
}
}
$arr2 = $psql->fetechAll(PDO::FETCH_ASSOC);
foreach($arr2 as $y){
if (!in_array($y['id'],$finalarray)) { // check id is already stored or not
$finalarray[] = $y['id'];
}
}
Maybe you should make sure which array is larger before your loop ;
Or using array_diff:
$finalarray = array_diff($array1 , $array2) ?? [];
$finalarray = array_merge( array_diff($array2 , $array1) ?? [], $finalarray );

Pushing an Array element into an existing multidimensional array in codeigniter

I have a query in codeigniter like this
$query_tutors = $this->db->get_where("tutor_info", array('tutor_id' => $tutor_id));
I have also other array elements that I want to pass in the query which depends on some conditions.
So how do I push other multidimensional array elements to the existing array so I can pass the variable as a whole in the query?
array_push is not working in this case.
$array = array();
$array = array("tutor_id" => $tutor_id);
$array = array("online" => $online); // want to merge this to the 1st array.
$query_tutors = $this->db->get_where("tutor_info", $array);
First you're doing it wrong.
$array = array();
$array = array("tutor_id" => $tutor_id);
You're recreating the array again, which will delete it from the memory. Either you have to use
$array['tutor_id'] = $tutor_id;
$array["online"] = $online;
or
$array = array('tutor_id' => $tutor_id, 'online' => $online);
or if you want to merge two arrays
$array = array_merge(array('tutor_id' => $tutor_id), array('tutor_id' => $tutor_id));
Your initial code
$array = [];
$array = ["tutor_id" => $tutor_id];
Now, if you want to add conditional merge, simply follow,
if($condition)
{
$array = array_merge($array, ["online" => $online]);
}
If $condition == true You final array will be,
$array = ['tutor_id' => $tutor_id, 'online' => $online];
You are almost there, just need to read a little bit more about associative arrays.
Solution:
$array = array();
$array["tutor_id"] = $tutor_id;
$array["online"] = $online;
$query_tutors = $this->db->get_where("tutor_info", $array);
This way your $array will have all indexes which you want.
You can do something like this:
$array = array();
if (!empty($tutor_id))
{
$array["tutor_id"] = $tutor_id;
}
if (!empty($online))
{
$array["online"] = $online;
}
$query_tutors = $this->db->get_where("tutor_info", $array);

PHP get first and forth value of an associative array

I have an associative array, $teams_name_points. The length of the array is unknown.
How do I access the first and forth value without knowing the key of this array in the easiest way?
The array is filled like this:
$name1 = "some_name1";
$name2 = "some_name2";
$teams_name_points[$name1] = 1;
$teams_name_points[$name2] = 2;
etc.
I want to do something like I do with an indexed array:
for($x=0; $x<count($teams_name_points); $x++){
echo $teams_name_points[$x];
}
How do I do this?
use array_keys?
$keys = array_keys($your_array);
echo $your_array[$keys[0]]; // 1st key
echo $your_array[$keys[3]]; // 4th key
You can use array_values which will give you a numerically indexed array.
$val = array_values($arr);
$first = $val[0];
$fourth = $val[3]
In addition to the array_values, to loop through as you show:
foreach($teams_name_points as $key => $value) {
echo "$key = $value";
}
You can get use the array_keys function such as
//Get all array keys in array
$keys = array_keys($teams_name_points);
//Now get the value for 4th key
//4 = (4-1) --> 3
$value = $teams_name_points[$keys[3]];
You can get all values now as exists
$cnt = count($keys);
if($cnt>0)
{
for($i=0;$i<$cnt;$i++)
{
//Get the value
$value = $team_name_points[$keys[$i]];
}
}

How do I select last array per key in a multidimensional array

Given the following php array
$a = array(
array('a'=>'111','b'=>'two','c'=>'asdasd'),
array('a'=>'111','b'=>'one','c'=>'sdvsdfs'),
array('a'=>'111','b'=>'three','c'=>'vbndfgn'),
array('a'=>'222','b'=>'nine','c'=>'dfhfnd')
);
how can I return only the last array per array key 'a'?
Desired result:
$new = array(
array('a'=>'111','b'=>'three','c'=>'vbndfgn'),
array('a'=>'222','b'=>'nine','c'=>'dfhfnd')
);
If I were you, I'd try to store it in a better format that makes retrieving it a bit easier. However, if you are stuck with your format, then try:
$a = array(
array('a'=>'111','b'=>'two','c'=>'asdasd'),
array('a'=>'111','b'=>'one','c'=>'sdvsdfs'),
array('a'=>'111','b'=>'three','c'=>'vbndfgn'),
array('a'=>'222','b'=>'nine','c'=>'dfhfnd')
);
$tmp = array();
foreach ($a as $value) {
$tmp[$value['a']] = $value;
}
$new = array_values($tmp);
print_r($new);

PHP - Automatically creating a multi-dimensional array

So here's the input:
$in['a--b--c--d'] = 'value';
And the desired output:
$out['a']['b']['c']['d'] = 'value';
Any ideas? I've tried the following code without any luck...
$in['a--b--c--d'] = 'value';
// $str = "a']['b']['c']['d";
$str = implode("']['", explode('--', key($in)));
${"out['$str']"} = 'value';
This seems like a prime candidate for recursion.
The basic approach goes something like:
create an array of keys
create an array for each key
when there are no more keys, return the value (instead of an array)
The recursion below does precisely this, during each call a new array is created, the first key in the list is assigned as the key for a new value. During the next step, if there are keys left, the procedure repeats, but when no keys are left, we simply return the value.
$keys = explode('--', key($in));
function arr_to_keys($keys, $val){
if(count($keys) == 0){
return $val;
}
return array($keys[0] => arr_to_keys(array_slice($keys,1), $val));
}
$out = arr_to_keys($keys, $in[key($in)]);
For your example the code above would evaluate as something equivalent to this (but will work for the general case of any number of -- separated items):
$out = array($keys[0] => array($keys[1] => array($keys[2] => array($keys[3] => 'value'))));
Or in more definitive terms it constructs the following:
$out = array('a' => array('b' => array('c' => array('d' => 'value'))));
Which allows you to access each sub-array through the indexes you wanted.
$temp = &$out = array();
$keys = explode('--', 'a--b--c--d');
foreach ($keys as $key) {
$temp[$key] = array();
$temp = &$temp[$key];
}
$temp = 'value';
echo $out['a']['b']['c']['d']; // this will print 'value'
In the code above I create an array for each key and use $temp to reference the last created array. When I run out of keys, I replace the last array with the actual value.
Note that $temp is a REFERENCE to the last created, most nested array.

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