Warning: preg_replace() code example

Example 1: preg_replace examples

$result = preg_replace('/abc/', 'def', $string);   # Replace all 'abc' with 'def'
$result = preg_replace('/abc/i', 'def', $string);  # Replace with case insensitive matching
$result = preg_replace('/\s+/', '', $string);      # Strip all whitespaces

Example 2: preg_replace examples

$result = preg_replace('/abc(def)hij/', '/\\1/', $string);
$result = preg_replace('/abc(def)hij/', '/$1/', $string);
$result = preg_replace('/abc(def)hij/', '/${1}/', $string);