Why do I get strange characters that are not in file?

Question

When I run this on my pc, I get "I am a file scsc"(without quotes) where sc is a strange character. (Such as @,#, etc. (Some sc are not even on keyboard).

When I use frm_file[20] , it prints "I am a file" (correct output).
Also, when I use frm_file[100] or 1000 or very larger values, I get correct output.

Why??
https://code.sololearn.com/cH9aceCVpk0r/?ref=app

Answer 1

Ok ~ swim ~ . I'll try this.
Thanks

Answer 2

Maybe Because in your file you have data more than 15 characters and you defined file size with 15 character.

Answer 3

🅰🅹 - ɪ'ᴍ ᴄʀɪᴍɪɴᴀʟʟʏ ɢᴏᴏᴅ! . The file has 11 characters + 1( null character)