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You prevent direct instance-variable 
access by marking instance variables with the private keyword.



You can, for example, redefine the Attraction class as follows, with 
minutes marked with the  
private keyword, rather than with the 
public keyword: 

public class Attraction { 
 // First, define instance variable: 
 private int minutes; 
 // Define zero-parameter constructor: 
 public Attraction () {minutes = 75;} 
 // Define one-parameter constructor: 
 public Attraction (int m) {minutes = m;} 
 // Define getter: 
 public int getMinutes () {return minutes;} 
 // Define setter: 
 public void setMinutes (int m) {minutes = m;} 
} 






With the Attraction class so redefined, attempts to access an 
attraction's instance-variable values from outside the Attraction 
class fail to compile: 

x.minutes      <-- Access fails to compile; 
                   the minutes instance variable is private 
x.minutes = 6  <-- Assignment fails to compile; 
                   the minutes instance variable is private