What are the potential issues with using echo statements in PHP to write data to a file like daten.txt?

Using echo statements to write data to a file like daten.txt can lead to potential issues such as including unwanted characters in the file or overwriting existing data. To solve this issue, it is recommended to use file handling functions like fopen, fwrite, and fclose to safely write data to the file.

$file = fopen("daten.txt", "a"); // "a" mode appends to the file
fwrite($file, "Data to be written\n");
fclose($file);