wrong description
The first time: division problem
Second time: error type 3 unknown encoding error (encoding GBK unmappable character)
Error cause analysis
When jdk is compiled, if the encoding format of the java source program is not specified with the -encoding parameter, javac first obtains the encoding format adopted by the operating system by default
When changing the division sign, I used the coding webpage to modify the comments online, which resulted in the 10th, 44th, 90th and other codes in the code being saved in a different coding method than the original GBK.
Solution
1. Use the -encoding parameter to specify the encoding method, and the class file can be successfully compiled
2. Delete comments
3. When modifying the code, modify it locally and upload it to coding
Problem index: javac error under cmd: unmappable character encoding GBK