PHP 'zip' arrays, like a zipper effect.

zipper.php

// Suppose you have 2 array and you want each value from array 2 to appear next to the value of array 1 with the same index...

$array1 = ['This', 'supposed', 'make', 'sentence'];
$array2 = ['is', 'to', 'a'];

$num1 = (count($array1) - 1) * 2;
$num2 = (count($array2) - 0) * 2;

$leftIndex    = $num1 > 0 ? range(0, $num1, 2) : [0];
$rightIndexes = $num2 > 2 ? range(1, $num2, 2) : [1];
$arr1 = array_combine($leftIndex, $array1);
$arr2 = array_combine($rightIndexes, $array2);
$array = $arr1 + $arr2;

// Rorder the array
ksort($array);

// Once the array is correct, we can create a new, nicely indexed array in case array1 and 2 have different number of values
$array = array_values($array);
echo implode(' ', $array);

// Output: This is supposed to make a sentence