get and set??

[Jeremy Parsons]

What do each of these get and set commands do? I've seen them in a study book, but they fail to mention what they do and are for..

[Sanjaya Sugiarto]

It's what is called encapsulation, an OO feature.

Imagine this:
without encapsulation

    
public class MyGrandMasAge {
   int grandMasAge;
 
   public void checkGrandMasAge() {
      if (grandMasAge<20) {
         System.out.println("not my grand ma");
      } else {
         System.out.println("perhaps...");
      }

Above code has a drawback. You can access the variable grandMasAge from other class without calling checkGrandMasAge for checking the age.

    
.....
MyGrandMasAge gma = new MyGrandMasAge();
gma.grandMasAge = -20; 
.....

Therefore we need whats called encapsulation getters/setters:

    
public class MyGrandMasAge {
   private int grandMasAge; //make it private, so that it can only be accessed in this class
   
   public void setGrandMasAge(int grandMasAge) {
      if [blablabla ...this.grandMasAge = grandMasAge ..blablabla..]
   }
 
   public int getGrandMasAge() {
      return grandMasAge;
   }

Above code has major benefit: you must set the age through the setGrandMasAge and get the value by calling getGrandMasAge. No way to directly calling the variable grandMasAge.

[Ilja Preuss]

There are no get and set commands in the Java language, so I guess you mean something different. Could you please elaborate? Are you asking about getter and setter *methods*?

[Michael Foo]

i think what he/she means is that the accessor and mutator methods..accessor methods, in your case..the get methods, allows you to get the data while the set methods, the mutator methods allows you to change the data

[Cameron Wallace McKenzie]

Getters and Setters are all about encapsulating data. In Java, we make instance variables private, which makes the data only directly accessible to the class, and we make the data accessible through public setter and getter method.

As we say, in Java, it's not polite to expose our privates.