php array_push and array_intersect - php

Question

I want to add value to array and then I want to use these arrays in array intersect. Codes are in bellow. Where am I doing mistake?
$array =['1,2,3,4','3,4,5','2,3'];
$arr2 = [];
$common = [];
for($i=0; $i<count($array); $i++)
{
$arr1 = [];
if($i==0)
{
array_push($arr1, $array[$i]);
array_push($arr2, $array[$i]);
$common = array_intersect($arr1,$arr2);
}
else
{
array_push($arr1, $array[$i]);
$common = array_intersect($arr1,$common);
}
print_r($common);
}
Output is :
Array (
[0] => 1,2,3,4
)
Array ( )
Array ( )
I want to be this :
Array (
[0] => 1,2,3,4
)
Array(
[0] => 3,4
)
Array(
[0] => 3
)
Thanks,

Answer 1

Try This
<?php
$array =['1,2,3,4','3,4,5','2,3'];
$arr1 = [];
for($i=0; $i<count($array); $i++)
{
$j='arr'.$i;
$j= [];
if($i==0){
array_push($j, $array[$i]);
}
else{
$a = explode(',',$array[$i-1]);
$b = explode(',',$array[$i]);
$c = array_intersect($a,$b);
$d= implode(',',$c);
array_push($j, $d);
}
echo "<pre>"; print_r($j);
}

Answer 2

You are misusing array_intersect. This method does works on values in an array not on a single value. To use it the way You want You should split your values by comma and insert them as separate values. For example:
value: '1,2,3,4' should be inserted as:
$array = ['1', '2', '3', '4'];
Solution (without loops etc):
<?php
$array =['1,2,3,4','3,4,5','2,3'];
$arr1 = array();
$arr2 = array();
$common = array();
$arr1 = explode(',', $array[0]);
$arr2 = explode(',', $array[1]);
$common =array_intersect($arr1, $arr2);
print_r($common);
$arr3 = explode(',', $array[2]);
$common2 = array_intersect($common, $arr3);
print_r($common2);
?>