get () and set () method is to get and set the mean, get only reference, set only assignment
A: Security
These two methods can only provide one for others, it can also set restrictions on the method, so that you can easily access and modify the class variables
II: Maintainability
Three: can control variables
With get () and set () you can control variables. If the get () and set () method which only put an assignment, then, and public variables should be no different. But imagine, if your variable score represents a student's math, in theory, could only score is an integer from 0 to 100, if you take the score to public, do not get () and set (), the user it is likely to enter a number other than 1 to 100, if you take the score to privata, then setScore () to set the score, you can control the behavior of the
original link: https: //blog.csdn.net / fututadeyoushang / article / details / 80941537
Four: As a norm, so many frameworks use
