Overriding vs Hiding

• Overriding is based on late binding (decided at runtime)
• Hiding is based on early binding (decided at compile time)
• Overriding examples:
  • non-static methods
• Hiding examples:
  • static methods
  • instance fields
  • static fields
• In hiding compiler only checks the declared type (datatype of the object) to determine which method/field to invoke
• It is not recommended to hide fields
• Hiding of fields happen even if their types are different
• ref: https://www.coderanch.com/wiki/659959/Overriding-Hiding

class Parent {
	// hiding
    public String name = "Parent";
    //hiding
    public static String staticName = "Parent";
    
    // only this supports overriding
    public String getName() {
        return "Parent";
    }
    // hiding
    public static String getStaticName() {
        return "Parent";
    }
}
 
class Child extends Parent {
    public String name = "Child";
    public static String staticName = "Child";
    public String getName() {
        return "Child";
    }
    public static String getStaticName() {
        return "Child";
    }
}
 
public class App {
    public static void main(String[] args) throws Exception {
        Parent obj = new Child();
        
        // Hiding non-static field + Hiding static field
        System.out.println(obj.name + " " + obj.staticName);
        // Parent Parent
 
        // Override non-static method + Hiding static method
        System.out.println(obj.getName() + " " + obj.getStaticName());
        // Child Parent
    }  
}