What is mutable and immutable in java
What you will learn here about mutable and immutable in java
- What is immutable in java
- What is mutable in java
What is immutable in java
In java Objects are called as immutable object whose states or properties can not be modify or change once it is assigned. For example String is immutable object in java.
public class Immutable { public static void main(String[] args) { //New object is created and reference assign to name variable String name="John"; //this will not create new object, it will assign reference of "John" to temp variable String temp=name; //This will create new Object and assign new reference to name name="John "+"Dow"; System.out.println(temp); System.out.println(name); } }
OUTPUT
John
John Dow
What is mutable in java
In java Objects are called as mutable object whose states or properties can be modify or change once it is assigned. For example consider there is a Student class and it has name and age are variable. Once we create an object of Student class we can also change the name and age of particular object using reference of that object.
public class Student { //instance variables String name; String lastName; int age; public Student() { } //Custom constructor public Student(String name,String lastName,int age) { this.name=name; this.lastName=lastName; this.age=age; } public static void main(String[] args) { //Object is created amd properties are set Student obj=new Student("John","Dow",20); System.out.println("name : "+obj.name+", Last name : "+obj.lastName+", age : "+obj.age); //changing lastname of obj obj.lastName="Cena"; //Object properties change means this muttable System.out.println("name : "+obj.name+", Last name : "+obj.lastName+", age : "+obj.age); } }
OUTPUT
name : John, Last name : Dow, age : 20
name : John, Last name : Cena, age : 20