Explode array's data and make new array

Question

I have this array:

Array
(
    [0] => Array
        (
            [0] => 1
            [1] => a,b,c
        )

    [1] => Array
        (
            [0] => 5
            [1] => d,e,f
        )
)

I want the final array to be this:

Array
(
    [0] => Array
        (
            [0] => 1
            [1] => a
        )

    [1] => Array
        (
            [0] => 1
            [1] => b
        )

    [2] => Array
        (
            [0] => 1
            [1] => c
        )

    [3] => Array
        (
            [0] => 5
            [1] => d
        )

    [4] => Array
        (
            [0] => 5
            [1] => e
        )

    [5] => Array
        (
            [0] => 5
            [1] => f
        )
)

This is what I did:

<?php
    $array = array(array(1,"a,b,c"),array(5,"d,e,f"));
    $temp=array();
    $count = 0;
    foreach($array as $arr){
        $rows = explode(",",$arr[1]);
        foreach($rows as $row){
            $temp[$count] = $arr;
            $temp[$count][1] = $row;
            $count++;
        }
    }
    print_r($temp);
?>

This totally works but I was wondering if there was a better way to do this. This can be very slow when I have huge data.

Using loops will generally be the fastest way. Often slowness is caused by inefficient loops, but that doesn't appear to be the case here. Your dataset would have to be genuinely MASSIVE for this to have a significant impact on the execution time of your script. — Scopey
– Scopey, Commented Apr 19, 2017 at 2:30
Yes. Loops will generally always be the fastest way. Using some callback function like array_map (not that this will work here) will be slower. — Scopey
– Scopey, Commented Apr 19, 2017 at 2:37

Ujjval Jha · Accepted Answer · 2017-04-19 03:24:41Z

1

Try like this way...

<?php

$array = array(array(1,"a,b,c"),array(5,"d,e,f"));
$temp=array();
$count = 0;
foreach($array as $arr){
    $rows = explode(",",$arr[1]);
    foreach($rows as $row){
        $temp[$count][] = $arr[0];
        $temp[$count][] = $row;
        $count++;
    }
}

/*print "<pre>";
  print_r($temp);
  print "<pre>";*/

?>

answered Apr 19, 2017 at 3:24

Ujjval Jha

3682 silver badges5 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

LIGHT Over a year ago

The problem is you copied the code from question itself, had to down vote you

Joe · Accepted Answer · 2017-04-19 10:51:00Z

1

Here's a functional approach:

$result = array_merge(...array_map(function(array $a) {
    return array_map(function($x) use ($a) {
        return [$a[0], $x];
    }, explode(",", $a[1]));
}, $array));

Try it online.

Or simply with two loops:

$result = [];
foreach ($array as $a) {
    foreach (explode(",", $a[1]) as $x) {
        $result[] = [$a[0], $x];
    }
}

Try it online.

Timing these reveals that a simple loop construct is ~8 times faster.

functional: 4.06s user 0.08s system 99% cpu 4.160 total
loop: 0.53s user 0.05s system 102% cpu 0.561 total

edited Apr 19, 2017 at 10:51

answered Apr 19, 2017 at 9:05

Joe

1,71611 silver badges10 bronze badges

2 Comments

LIGHT Over a year ago

Is it faster than what we have?

Joe Over a year ago

@Prakash: Nope, actually a lot slower than by simply looping the array. I've modified my answer accordingly.

Rahul · Accepted Answer · 2017-04-19 05:36:54Z

0

If you need other way around,

$array = array(array(1, "a,b,c"), array(5, "d,e,f"));
$temp  = [];
array_walk($array, function ($item, $key) use (&$temp) {
    $second = explode(',', $item[1]);
    foreach ($second as $v) {
        $temp[] = [$item[0], $v];
    }
});
print_r($temp);

array_walk — Apply a user supplied function to every member of an array

Here is working demo.

answered Apr 19, 2017 at 5:36

Rahul

18.6k7 gold badges43 silver badges64 bronze badges

Collectives™ on Stack Overflow

Explode array's data and make new array

3 Answers 3

1 Comment

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related