PHP键值对，其中键是动态变量，值是数组？

Question

I am trying to create a 2D array where $multiples[$i] = array(multiples of $i), $i = 1,2,3...

function getMultiples($factor, $start = 0, 10)
{
  $multiples = array();

  for($i = $factor + $start; $i < 10; $i+=$factor)
  $multiples[] = $i;

  return $multiples;
}

for($i = 2; $i < 10; $i++)
{
    $start = 0 ;

    $multiples[$i] = getMultiples($i, $start, 10);
}

However, when I var_dump

$multiples[2] = array(0 => 2)
$multiples[3] = array(0 => 3)
$multiples[4] = array(0 => 4)
...

Each element of $values has been intialized with only the first multiple in each array.

I've tested this with non-numerical key values and it works fine. Static key values also work. The dynamic key value $i seems to the problem, what is going on here?

Answer 1

If you want to get the multiples of a number, you need to update the getMultiples as following:

function getMultiples($factor, $start = 0, $max)
{
  $multiples = array();

  for($i = 2; $i < $max; $i++)
  $multiples[] = $i*$factor;

  return $multiples;
}

What we change?

1. Loop 10 or $max time for($i = $factor + $start; $i < 10; $i+=$factor) to for($i = 2; $i < $max; $i++).
2. Find multiple $multiples[] = $i; to $multiples[] = $i*$factor;