200 lines of Java code to write a calculator program

I found a calculator applet written in college and a graphical interface that can graphically display the expression syntax tree, ha ha;)

With only 200 lines of Java code, it can not only calculate addition, subtraction, multiplication and division, but also match parentheses~

Code comments:

From simple interface color matching to easy to understand error tips, all reflect the design concept of "user experience" first; The code exception handling is comprehensive and reasonable without leakage, the code indentation is elegant and generous, and the variable naming is intuitive and easy to understand; Combined with the notes of moderate length, simple and clear, the whole program gives people a fresh and refined feeling. It is not difficult to see the author's love for learning and demanding on design. The craftsman spirit can be seen. It can really be described as a model for the application of university data structure learning!

The implementation code is as follows:

summary

The above is 200 lines of Java code introduced to you by Xiaobian. I hope to write a calculator program. If you have any questions, please leave me a message and Xiaobian will reply to you in time. Thank you very much for your support of programming tips!