How can PHP developers efficiently extract content between specific characters in a string?

To efficiently extract content between specific characters in a string, PHP developers can use the `strpos()` function to find the positions of the start and end characters, and then use `substr()` to extract the content between those positions.

$string = "This is a [sample] string with [multiple] brackets";
$start = strpos($string, "[") + 1;
$end = strpos($string, "]", $start);
$extracted_content = substr($string, $start, $end - $start);
echo $extracted_content; // Output: sample