Array keep on repeating in foreach - php

Question

I have an array holding string in it's values, I am finding underscore in each value breaking it and inserting it into new array, It's doing all right but only for first array in second array it repeats first array also.
For Example
$someArraVal[] = 'abc_xyz__vr1_vr2';
$someArraVal[] = 'emf_ccc__vr2_vr3';
First I am getting everything after double underscore then exploding them with underscore and trying to have array like below
Array
(
[0] => Array
(
[0] => vr1
[1] => vr2
)
[1] => Array
(
[2] => vr3
[3] => vr4
)
)
but I am getting
Array
(
[0] => Array
(
[0] => vr1
[1] => vr2
)
[1] => Array
(
[0] => vr1
[1] => vr2
[2] => vr3
[3] => vr4
)
)
CODE
$someArraVal[] = 'abc_xyz__vr1_vr2';
$someArraVal[] = 'emf_ccc__vr3_vr4';
$arr1 = [];
$arr2 = [];
$xmx = [];
foreach ($someArraVal as $key => $value) {
$afterunderscore = substr($value, strpos($value, "__") + 1);
// $addPipe = str_replace("_","|",$afterunderscore);
$abc = substr($afterunderscore, 1);
$arr1 = explode('_',$abc);
foreach ($arr1 as $k => $v) {
$arr2[] = $v;
}
$xmx[] = $arr2;
}
printR($xmx);

Answer 1

You need to empty the array $arr2 at the start of foreach loop.
.
.
.
foreach ($someArraVal as $key => $value) {
$arr2 = []; //Empty the $arr2 at begining of the loop
.
.
.
}

Answer 2

You never reset $arr2 so you append more data each iteration.
You can add $arr2 = [] right after the foreach.
Better solution will be to do:
foreach ($someArraVal as $key => $value) {
$afterunderscore = substr($value, strpos($value, "__") + 1);
$xmx[] = explode('_',substr($afterunderscore, 1));
}
Live example: 3v4l

Answer 3

Second array keeps repeating because you are looping inside the array which will take all the values.
<?php
$someArraVal[] = 'abc_xyz__vr1_vr2';
$someArraVal[] = 'emf_ccc__vr3_vr4';
$arr1 = [];
foreach ($someArraVal as $key => $value) {
$afterunderscore = substr($value, strpos($value, "__") + 1);
$abc = substr($afterunderscore, 1);
$arr1[] = explode('_',$abc);
}
echo '<pre>';
print_r($arr1);
echo '</pre>';
Please check : https://prnt.sc/oitez2

Answer 4

Another technique using a single iterated function call...
Code: (Demo)
$someArraVal[] = 'abc_xyz__vr1_vr2';
$someArraVal[] = 'emf_ccc__vr2_vr3';
foreach ($someArraVal as $value) {
$xmx[] = preg_split('~(?:[^_]+_)*_~', $value, 0, PREG_SPLIT_NO_EMPTY);
}
print_r($xmx);
Output:
Array
(
[0] => Array
(
[0] => vr1
[1] => vr2
)
[1] => Array
(
[0] => vr2
[1] => vr3
)
)
The pattern consumes the undesired substrings and treats them as delimiters. This leaves you with only the substrings that you want.
If the idea of regex scares you, here's a non-regex solution with just two calls per iteration:
foreach ($someArraVal as $value) {
$xmx[] = array_slice(explode('_', $value, 5), -2);
}
// same result array