To write an api today, I need to call an api interface of a third party, but during the test, I found that the returned data is always different from what I saw during debugging. Various tests showed that adding trim() to modify the code, but the result was very stubborn, so The loop string is output as char[], but I still don't see the difference, so I see a special number 65279 in the int output. After Baidu, I found the reason may be because I have written code with non-standard tools such as Notepad and added BOM. , here are two links you can refer to this issue
Problems encountered with unicode character 65279 (ZERO WIDTH NO-BREAK SPACE) in text processing