Static in Java
Static In Java
The static keyword in Java is used to share the same variable or method of a given class. You can use static keywords with variables, methods, blocks, nested classes, etc. The static keyword belongs to the class. In Java, a static keyword is used for memory management.
Demo Example
class Database{
static String host = "localhost";
}
public class Main {
public static void main(String[] args) {
// We can get static properties by Classname.propertiesName
System.out.println("Database host is "+Database.host);
}
}
Static Methods
When the method is declared with a static keyword, then that method is called a static method.
class Database{
// static method
static String getInfo(){
return "localhost";
}
}
public class Main {
public static void main(String[] args) {
// We can get static method by Classname.methodName
System.out.println("Database host is "+Database.getInfo());
}
}
When to use static variables and methods?
You can use a static keyword that is common for all use cases. E.g., In database host, database name, username, password, etc. We can store it on a static keyword.
Other Example Of Static
Here in this example, school is shared between all objects. We don’t need to set school for every student.
public class Main {
public static void main(String[] args) {
// we can access static value by Classname.propertyname. It can be shared to all objects.
Student.school = "Hiway School";
Student s1 = new Student();
s1.name = "Bikash";
s1.address = "USA";
s1.email = "[email protected]";
Student s2 = new Student();
s2.name = "Menuka";
s2.address = "USA";
s2.email = "[email protected]";
// we don't need to set the school
System.out.println("School of "+s1.name +" : "+s1.school);
System.out.println("School of "+s2.name +" : "+s2.school);
}
}
class Student{
String name;
String address;
String email;
// here school is declared as static.
static String school;
}