Forced Conversion to Floating-Point Numbers in PHP

Suppose we now have a string with a floating-point number:

php<?php
  $test = '1.2';
  var_dump($test);
?>

To convert this string to a number, you should use the float command:

php<?php
  $test = (float) '1.2';
  var_dump($test); // outputs 1.2
?>

Задание 1

Convert the following string to a number:

php<?php
  $test = '12.345';
?>