With default case sensitive condition which is false the output is error and with condition true output is shown explain plz

Question

https://code.sololearn.com/wS3GO4wwK56w/?ref=app
https://code.sololearn.com/wpU25U8oPMY7/?ref=app

Answer 1

Constants declared with define() are case-sensitive by default.

It is possible to declare case-insensitive constants by passing true as the third parameter of define().

https://wiki.php.net/rfc/case_insensitive_constant_deprecation

Answer 2

Thx U