mysql-backup | Backup MySQL | Continuous Backup library

Using PHP, I want to generate custom MySQL dump file (due to cannot use exec and a few other reasons). So I found these 2 similar solutions:

1. https://www.kvcodes.com/2017/10/php-create-mysql-backup
2. https://davidwalsh.name/backup-mysql-database-php

The different part that I want to highlight is:

Link 1: $row[$j] = preg_replace("#\n#", "\\n", $row[$j])

Link 2: $row[$j] = ereg_replace("\n","\\n",$row[$j])

I know that ereg_replace() is depreciated. I also assume that there's typo in solution Link 1 which should be:

$row[$j] = preg_replace("\n", "\\n", $row[$j])

But then in my solution, I simply use:

$row[$j] = str_replace("\n", "\\n", $row[$j])

So my question is, how could I be wrong by using str_replace()? I've tested dumping several complex data (json, coding, html syntax) and all seems ok. Could there some special case that str_replace() would handle differently than preg_replace()?

Conslusion:

Based on all feedbacks here, I changed my solution similar to Link 1 because its more bullet proof across platform.