Important Observations of Reflection API

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  1. We can invoke an method through reflection if we know its name and parameter types. We use below two methods for this purpose
    getDeclaredMethod() : To create an object of method to be invoked. The syntax for this method is
    Class.getDeclaredMethod(name, parametertype)
name- the name of method whose object is to be created
parametertype - parameter is an array of Class objects

    invoke() : To invoke a method of the class at runtime we use following method–

    Method.invoke(Object, parameter)
If the method of the class doesn’t accepts any 
parameter then null is passed as argument.
  2. Through reflection we can access the private variables and methods of a class with the help of its class object and invoke the method by using the object as discussed above. We use below two methods for this purpose.

    Class.getDeclaredField(FieldName) : Used to get the private field. Returns an object of type Field for specified field name.
    Field.setAccessible(true) : Allows to access the field irrespective of the access modifier used with the field.

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