Static Keyword in Java

static keyword is mainly used for memory management. We can be use with .

Variables
Methods
Blocks
Nested classes. e.t.c

1) Static Variable in Java

→ When a variable is declared as static, it is called static variable.

→ static variable refer to the common property of all objects.

→ static variable gets memory only once in the class area at the time of class loading.

Example 1:

 class Student{  
       int id;
       String name;
       static String course="Engineer";  //static variable
       Student(int i,String n){   //constructor here  
        
        id=i;
        name=n;
      } void show() //method to display here
          {
            System.out.println(id+ " ," +name+ ", " +course);
          }
    public static void main(String args[]){  
     Student s1 = new Student(01,"Priyanka");
     Student s2 = new Student(01,"Pradeep");   
     s1.show();
     s2.show();
     }  
  }  

Output

Example 2: Change the course.

 
class Student{  
       int id;
       String name;
       static String course="Engineer";  //static variable
     Student(int i,String n)  //constructor here  
          {
        id=i;
        name=n;
      } 
    void show() //method to display here
          {
            System.out.println(id+ " ," +name+ ", " +course);
          }
    public static void main(String args[]){  
     Student s1 = new Student(01,"Priyanka");
     Student s2 = new Student(01,"Pradeep");   
     Student.course="Diploma";  //change the course
     s1.show();
     s2.show();
     }  
  }  

Output

2) static method in Java

static method can access the static data member and can change the value of it.
When a method is declared with the static keyword, it is known as a static method.

Example : Change the course.

 
   class Student{  
       int id;
       String name;
       static String course="Engineer";  //static variable
      static void change() // Method here
     {  
       course = "Doctor";  
     }  
      Student(int i,String n)  //constructor here  
          {
        id=i;
        name=n;
      } 
    void show() //method to display here
          {
            System.out.println(id+ " ," +name+ ", " +course);
          }
    public static void main(String args[]){  
       Student.change(); // calling to method
     Student s1 = new Student(01,"Priyanka");
     Student s2 = new Student(01,"Pradeep");   
     s1.show();
     s2.show();
     
     }  
  }  

Output

3) Static block in Java

Is used to initialize the static data member or static variables..
Static block is executed once when the first object of the class is created.
It is executed before the main method at the time of classloading.

Example :

class StaticBlockEx{  
  static{System.out.println("static block Example");}  
  public static void main(String args[]){  
   System.out.println("Hello , How are you");  
  }  
}  

Output

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OOPs Concepts

Static Keyword in Java

1) Static Variable in Java

2) static method in Java

3) Static block in Java

Example :