PHP: How to delete all array elements after an index

Question

Is it possible to delete all array elements after an index?

$myArrayInit = array(1=>red, 30=>orange, 25=>velvet, 45=>pink);

now some "magic"

$myArray = delIndex(30, $myArrayInit);

to get

$myArray = array(1=>red, 30=>orange);

due to the keys in $myArray are not successive, I don't see a chance for array_slice()

Please note : Keys have to be preserved! + I do only know the Offset Key!!

score 27 · Accepted Answer · edited Mar 28 '19 at 22:46

27

Without making use of loops.

<?php
    $myArrayInit = [1 => 'red', 30 => 'orange', 25 => 'velvet', 45 => 'pink']; //<-- Your actual array
    $offsetKey = 25; //<--- The offset you need to grab

    //Lets do the code....
    $n = array_keys($myArrayInit); //<---- Grab all the keys of your actual array and put in another array
    $count = array_search($offsetKey, $n); //<--- Returns the position of the offset from this array using search
    $new_arr = array_slice($myArrayInit, 0, $count + 1, true);//<--- Slice it with the 0 index as start and position+1 as the length parameter.
    print_r($new_arr);

Output :

Array
(
    [1] => red
    [30] => orange
    [25] => velvet
)

edited Mar 28 '19 at 22:46

Mohamed Mo Kawsara

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answered Feb 18 '14 at 10:45

Shankar Narayana Damodaran

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4

I think your answer is more good coz it preserve the key association :) – Nouphal.M Feb 18 '14 at 10:47
1

Thanks sankar to let me notice the 4th arg of array_slice :) – Nouphal.M Feb 18 '14 at 10:55
1

guys, you are so phantastic!!! Thank you VERY VARY VERY VERY MUCH!!! – Viktor Feb 18 '14 at 10:55

Nouphal.M · Answer 2 · 2014-02-18T15:45:27.527

4

Try

$arr = array(1=>red, 30=>orange, 25=>velvet, 45=>pink);
$pos = array_search('30', array_keys($arr));
$arr= array_slice($arr,0,$pos+1,true);
echo "<pre>";
print_r($arr);

See demo

edited Feb 18 '14 at 15:45

answered Feb 18 '14 at 10:45

Nouphal.M

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**But the keys are not preserved.** – Shankar Narayana Damodaran Feb 18 '14 at 10:46
If the OP doesn't care about it, then yours is the best :) – Shankar Narayana Damodaran Feb 18 '14 at 10:50
that does delete the prev elements, not the following – Viktor Feb 18 '14 at 10:50
Ooops.. I will update my answer – Nouphal.M Feb 18 '14 at 10:51
2

@viktor have updated my answer. But Sankar deserves the correct answer – Nouphal.M Feb 18 '14 at 10:57
@Nouphal.M, If you replace `$pos` with `$pos+1` you will get the correct result... currently it shows just the `red` skipping `orange`. – Shankar Narayana Damodaran Feb 18 '14 at 15:35
My **+1** mate. Welcome to 4K club :) – Shankar Narayana Damodaran Feb 18 '14 at 16:41
Code only answers are low value on SO. – mickmackusa Nov 29 '17 at 19:58

score 2 · Answer 3 · answered Feb 18 '14 at 10:42

2

I'd iterate over the array up until you reach the key you want to truncate the array thereafter, and add those items to a new - temporary array, then set the existing array to null, then assign the temp array to the existing array.

answered Feb 18 '14 at 10:42

i-CONICA

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score 1 · Answer 4 · answered Feb 18 '14 at 10:47

1

This uses a flag value to determine your limit:

$myArrayInit = array(1=>'red', 30=>'orange', 25=>'velvet', 45=>'pink');

$new_array = delIndex(30,$myArrayInit);

function delIndex($limit,$array){

    $limit_reached=false;

    foreach($array as $ind=>$val){

        if($limit_reached==true){
            unset($array[$ind]);
        }
        if($ind==$limit){
            $limit_reached=true;
        }

    }
    return $array;
}
print_r($new_array);

answered Feb 18 '14 at 10:47

AyB

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**+1** The above code also preserves the key-association and also no `array functions` were used ! – Shankar Narayana Damodaran Feb 19 '14 at 04:23

Sabri Aziri · Answer 5 · 2017-12-06T11:43:56.293

0

Try this:

function delIndex($afterIndex, $array){
    $flag = false;
    foreach($array as $key=>$val){
        if($flag == true)
            unset($array[$key]);
        if($key == $afterIndex)
             $flag = true; 
    }
    return $array;
}

This code is not tested

edited Dec 06 '17 at 11:43

answered Feb 18 '14 at 10:43

Sabri Aziri

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Code only answers are low value on SO. – mickmackusa Nov 29 '17 at 19:58

PHP: How to delete all array elements after an index

5 Answers5

Without making use of loops.

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