将php整数转换为字符串到数组？

Question

I wrote this function that takes a number and formats it with commas, so every three digits from right-to-left, a comma as added.

It works, but there is this error of "unitialized string offset" which I found was due to me treating the string as an array.

I decided to post my code to also see if there was a more straight forward way to do this.

Otherwise, my main question is how can I turn that string into an array?

I tried to use str_split but it broke my code/page.

<?php

  // comma function
  function commaCreate($num) {
    // convert number to string
    $int_string = strval($num);
    // turn $int_string into an array (omitted as it doesn't work)
    // $int_string = str_split($int_string);
    // get length of string
    $int_length = strlen($int_string);
    // create variables
    $counter          = 0;
    $formatted_number = "";
    // run through number right-to-left
    for ($i = $int_length; $i >= 0; $i--) {
      if ($counter == 3) {
        // add number
        $formatted_number = $int_string[$i].$formatted_number;
        // add comma
        if ($i != 0) {
          $formatted_number = ",".$formatted_number;
        }
        // reset counter
        $counter = 0;
        $counter++;
      }
      else {
        $formatted_number = $int_string[$i].$formatted_number;
        $counter++;
      }
    }
    // output formatted number
    echo $formatted_number;
  }

  commaCreate(300000); // outputs 300,000

?>

I think I just realized what I could have done had I chosen to pursue this route.

I'd just go through the string (as an array cringe) and add it to an array.

something like

$array      = array();
$num_string = strval($num);
$num_length = strlen($num_string);
for ( $i = 0; $i < $num_length; $i++) {
    $array = $num_string[$i];
}

I think that would work, not sure, would have to try it, but I have a solution that's much simpler already thanks to akDeveloper

Answer 1

PHP "$" variables include every type of variables. You just need some tricks to convert any variable to what you want. For example:

$n = 12345; // This is integer
$s = $n.""; // Now $s is string. 
echo $s[2]; // Now $s is array. 

OUTPUT: "3". as $n at 2 = 3