how to call a method in java from another class code example

Example 1: how to call a function from a class java

public class Classroom {
	 private String teacherName;
	
  	 public Classroom(String teacherName){
       this.teacherName = teacherName;
     }
  
  	 public String getTeacherName() {
        return teacherName;
     } 
}

public static void main(String[] args){
	Classroom firstGrade = new Classroom("John");
    /*Once you type the 'firstGrade.' your IDE most likely 
	will show all the functions it can acess*/
    firstGrade.getTeacherName();
}

Example 2: java use method in another class

class A { 
  
    public void a1 ( ) { 
    } 
 
    private void a2 ( ) { 
    } 
} 
 
class B { 
 
    private A objA = new A ( ); 
 
    public void b1 ( ) { 
        // Call to method a1. This works. 
        objA.a1 (); 
    } 
 
    void b2 ( ) { 
        // Call to method a2. This will give compile error. 
        objA.a2 (); 
    } 
}

Example 3: how to access methods from another class in java

public class Alpha extends Beta{
     public void DoSomethingAlpha() {
          DoSomethingBeta();  //?
     }
}

Example 4: how to access methods from another class in java

public class Alpha {
     public void DoSomethingAlpha() {
          Beta cbeta = new Beta();
          cbeta.DoSomethingBeta();  //?
     }
}