Question 40234 in PHP Question posted in
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PHP sort certain numbers from an array

trying to solve a kata here where the instructions are:

You will be given an array of numbers. You have to sort the odd numbers in ascending order while leaving the even numbers at their original positions.

Examples

[7, 1]  =>  [1, 7]
[5, 8, 6, 3, 4]  =>  [3, 8, 6, 5, 4]
[9, 8, 7, 6, 5, 4, 3, 2, 1, 0]  =>  [1, 8, 3, 6, 5, 4, 7, 2, 9, 0]

I come up with this code

function sortArray(array $arr) : array {
  $oddNumbers = [0];
  $oddNumbersPlaced = 0;
  for ($i = 0; $i < count($arr); $i++)
    if ($arr[$i] % 2 != 0) {
      $oddNumbers[$oddNumbersPlaced] = $arr[$i];
      $arr[$i] = 'a';
      $oddNumbersPlaced =+ 1;
     };
    
  $oddNumbers = sort($oddNumbers);
  
  for ($n = 0; $n < count($arr); $n++){
    $oddPlaced = 0;
    if ($arr[$n] == 'a'){
      $arr[$n] = $oddNumbers[$oddPlaced];
      $oddPlaced = $oddPlaced+1;
    }
  }
  return $arr;
}

but get an error at line 17 :

$arr[$n] = $oddNumbers[$oddPlaced];

which says ‘Trying to access array offset on value of type bool’;

can someone explain to me how and where do i get a bool value plz ?

Tags:

2

Answers


  1. 0

    Do not assign

    sort($oddNumbers);

    to

    $oddNumbers

    because sort always return true, it accepts pass by reference.

    Example:

    // Create an array of odd numbers
$oddNumbers = [7, 1, 5, 9, 3];

// Sort the array in ascending order using the sort() function
sort($oddNumbers);

// Print the sorted array
print_r($oddNumbers);

    will result in

    Array
(
    [0] => 1
    [1] => 3
    [2] => 5
    [3] => 7
    [4] => 9
)
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  2. 0

    Like that?

    <?php
$array = [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]; // ...,2,9,0
$odds = [];
$even = [];

foreach ($array as $val) 
{
    if($val % 2 !== 0) 
    {
        $odds[] = $val;
    } 
    else 
    {
        $even[] = $val;
    }
}

sort($odds);
rsort($even);

$array = [];
foreach ($odds as $key => $val) 
{
    $array[] = $val;
    if(isset($even[$key])) 
    {
        $array[] = $even[$key];
    }
}

print_r($array);
// output:
Array
(
    [0] => 1
    [1] => 8
    [2] => 3
    [3] => 6
    [4] => 5
    [5] => 4
    [6] => 7
    [7] => 2
    [8] => 9
    [9] => 0
)
    Login or Signup to reply.
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