The static keyword in java is used for memory management mainly. We can apply java static
keyword with variables, way(method) s, blocks and nested class. The static keyword belongs to
the classthan instance of the class.
The static can be:
1. variable (also known as class variable)
2. way(method) (also known as class way(method) )
3. block
4. nested class
Java static variable
If you declare any variable as static, it is known static variable.
1. The static variable can be used to refer the frequentproperty of all objects (that is not unique for
each object) e.g. company name of workers,college name of codings etc.
2. The static variable gets memory only once in class area at the time of class loading.
Advantage of static variable
It makes your program memory efficient (i.e it saves memory).
Understanding problem without static variable
1. class Coding{
2. int rollno;
3. String name;
4. String
college=”LNCTU”;5. }
Example of static variable
//Program of static variable
class Coding8{
int rollno;
String name;
static String college
=”LNCTU”;
Coding8(int r,String n){
rollno = r;
name = n;
}
void display (){System.out.println(rollno+” “+name+” “+college);}
public static void main(String args[]){
Coding8 s1 = new
Coding8(111,”Rawan”);
Coding8 s2 = new Coding8(222,”Ram”);
s1.display();
s2.display();
} }
Output:111 Rawan LNCTU
222 Ram LNCTU
Java static way(method)
If you apply static keyword with any way(method) , it is known as static way(method) .
1. A static way(method) belongs to the class rather than object of a class.
2. A static way(method) can be produce without the need for creating an instance of a class.
3. static way(method) can entrance static data member and can change the value of it.
Example of static way(method)
//Program of changing the frequentproperty of all objects(static field).
class Coding9{
int rollno;
String name;
static String college = “LNCTU”;
static void change(){
college = “LNCT”;
}
Coding9(int r, String n){
rollno = r;
name = n;
}
void display (){System.out.println(rollno+” “+name+” “+college);}
public static void main(String args[]){
Coding9.change();
Coding9 s1 = new Coding9 (111,”Rawan”);
Coding9 s2 = new Coding9 (222,”Ram”);
Coding9 s3 = new Coding9 (333,”Sonoo”);
s1.display();
s2.display();
s3.display();
} }
Output:111 Rawan LNCT
222
Ram LNCTU
Java static block
4. Is used to institute the static data member.
5. It is applied before main way(method) at the time of class loading.
Example of static block
class A2{
static{System.out.println(“progmarcoding is
produce”);}
public static void main(String args[]){
System.out.println
(“Hello main”);
}}
Output: progmarcoding is
generate
Hello main