ENCAPSULATION
Hello
guys, today we are gonna talk about encapsulation, which is another pillar of
OOps in java. So what is encapsulation? Consider a capsule, a capsule consists
of powdered medicines which is enclosed in an outer body ,and the pateint who
eats the capsule doesn't know that what powdered medicines are actually inside
the capsule. So encapsulation is sort off same thing, we write our code but we
encapsulate or hide our certain data and so that everyone can't access every
data that is inside our code. So the key point of encapsulation is data privacy
but apart from that it also allows us to set a certain criteria for taking the
parameters from the user.
First
let us see it's implementation inside the code
Ex:
package solution;
public class Student {
private int marks;
private String name;
public int getMarks() {
return marks;
}
public void setMarks(int age) {
this.marks = marks;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
The
first step is to create a separate class file inside the same package where
your class with main method exists. Make sure your each variable inside this
class should be public, and then finally we can create a getter and setter
method (shown below in the example) for each of our parameters inside the class
(make sure they are public too).
Note
that, this keyword is a reference variable use to reference the current object.
Now
we can create an object out of this class inside our main method and call them
respectively. The code (that has to be in the main method) is given below
package solution;
public class Coding_Winds {
public static void main(String[] args) {
Student obj = new Student();
obj.setMarks(18);
obj.setName("Mr. Moolchand");
}
}
Now if we can print out the inputs that we passed
package solution;
public class Coding_Winds {
public static void main(String[] args) {
Student obj = new Student();
obj.setMarks(18);
obj.setName("Mr. Moolchand");
System.out.println("The name of the student is "+obj.getName()+" and his/her score is "+obj.getMarks()+"/20");
}
}
//Output: The name of the student is Mr. Moolchand and
his/her score is 18/20
Now
this was one thing, what if you want your parameters to be filtered out through
a certain criteria? Yes, encapsulation allows us to set the criteria for
parameters inside our setter method. Look at the code below
package solution;
public class Student {
private int marks;
private String name;
public int getMarks() {
return marks;
}
public String getName() {
return name;
}
public void setName(String name) {
if(name.length()>=20)
{
System.out.println("Your nick name
please!");
}
else {
System.out.println("The name of the
student :"+name);
}
this.name = name;
}
public void setMarks(int marks) {
if(marks>20) {
System.out.print("Invalid Score!");
}
else if(marks>17) {
System.out.print("Grade: A grade");
}
else if(marks>14) {
System.out.print("Grade: B grade");
}
else if(marks >11) {
System.out.print("Grade: C grade");
}
else if(marks > 8) {
System.out.print("Grade: D grade");
}
else {
System.out.print("Failed");
}
this.marks = marks;
}
}
Now if the user will enter the name that has more than 20
characters or a score that is more than 20, the output will come as shown below
the code
package solution;
public class Coding_Winds {
public static void main(String[] args) {
Student obj = new Student();
obj.setName("Mr. Bala subramanium Ji");
obj.setMarks(22);
}
}
/*Your nick name please!
Invalid Score!
*/
Similarly
if the user will make sure of the parameters criteria, the output will come
accordingly. For example
package solution;
public class Coding_Winds {
public static void main(String[] args) {
Student obj = new Student();
obj.setName("Jessica Davis");
obj.setMarks(15);
}
}
/*The name of the student :Jessica Davis
Grade: B grade
*/
So
this was all about encapsulation, we will keep catching up with you along with
more hot blogs. Till then keep reading, and keep coding.
If you still have any doubt on this topic then do come to us via email "sophomoretechs@gmail.com" or via Instagram "@coding.winds".
This article is SUBMITTED By : Pranjal Rai
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