Object Array

[Vishnu Khera]

class RefAssignment2 {

@Override
    public String toString() {
        return "Class RefAssignment2";
    }
}



class ObjectArray {
    public static void main(String[] args) {
            
            
        Boolean bool = true;
        
        int[] newArray = new int[] {5,47,3,8,};
        
        Object[] check = new Object[] { "hello world!", newArray, bool, new RefAssignment2() };
        
        for(Object obj : check) {
            System.out.println(check[<<<<<what do we put here???>>>>>]);
        }
        
        System.out.println(check[1]); /* check[1] gives us reference to an array - how do we print elements of this array??
        
                                        and at the same time check what (type) we are referring to - accordingly print 
                                        
                                        necessary details?*/
    }
}

I have placed my questions within the code.

[harshvardhan ojha]

Hi Vishnu, you need to check your beans
I am providing you code snippet here for help

BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass());
System.out.println(beanInfo.getBeanDescriptor().getBeanClass());

Hope this will help.

[Jeff Verdegan]

Vishnu Khera wrote:

        for(Object obj : check) {
            System.out.println(check[<<<<<what do we put here???>>>>>]);

You don't need check[whatever] there. You already have the current element in the obj variable.

This:

for (Object obj : check) {
   // do stuff
}

is equivalent to this:

for (int i = 0; i < check.length; i++) {
  Object obj = check[i];
  // do stuff
}

[Red Smith]

Vishnu Khera wrote:

        for(Object obj : check) {
            System.out.println(check[<<<<<what do we put here???>>>>>]);
        }

That version of the for statement would not use check with an index, e.g.: check[i] the way this version does:

 for (int i = 0; i < check.length; i++)

The version you are using puts each check element into obj as it loops. So you access obj each time, not check with a subscript.

Vishnu Khera wrote:

        System.out.println(check[1]); /* check[1] gives us reference to an array - how do we print elements of this array??
                                        and at the same time check what (type) we are referring to - accordingly print  necessary details?*/

obj.getClass().getCanonicalName() will give the type that you can do a String compare on or use instanceof with.

[Vishnu Khera]

Jeff and Red, you are awesome Thank you so much

Oops.. this was a very easy one got carried away with all these concepts of arrays, reference type - type conversions

getCanonicalName() was really helpful