Winter vacation preparation provides some practical training guidance to students

I applied for a practical training base some time ago and it never worked. Just these two days, some people asked me how to learn Java during the winter vacation. In order to improve everyone's hands-on ability, I plan to give you some practical questions during the winter vacation for you to practice.

Method used: 1. I will give a question. 2. Do it, show the code, and discuss the code. 3. No. I will give the answer. Statement: I will not do these questions in advance.

Purpose: To improve everyone's hands-on ability, specifically the ability to write and debug code.

The first question has been posted. Please check it out.

Training 1: File Operations

Training 2: Add a random number (some trainees have already given the answer to training 1) 2010.1.20