Source code and handouts can be obtained from Q group: 589912610; 1. Why do you need to learn object-oriented PHP? Object-oriented is an advanced content of programming, which is relatively difficult to understand, but there is not much syntax knowledge. Common various PHP frameworks are based on object-oriented: laravel, thinkphp, etc. Although object-oriented preparation work is relatively tedious in the early stage, the later application is extremely convenient. The various classes written by yourself can be flexibly used in various projects. Only by mastering object-oriented can we step into the mysterious door of programming, allowing us to have new ideas on more issues. 2. What can you do after learning object-oriented? Construct common functional classes: database operation class (to realize the addition, deletion, modification and query of data table information and database link), user verification class (to realize user login, user registration and logout),