Question on Object and equals

[Win jones]

Hello,
Can someone explain the working of the code below

class test{
public static void main(String [] arg) {
 
Boolean b1 = new Boolean(true);
Boolean b2 = new Boolean(true);
 
Object obj3 = new Object();
Object obj4 = new Object();
 

Object obj1 = (Object)b1;
Object obj2 = (Object)b2;
 
if (obj3.equals(obj4))  [B]//why is this false [/B]
if (obj1.equals(obj2))
System.out.println("a");
else
System.out.println("b");
else
if (obj1.equals(obj2)) [B]//why is this true[/B]
System.out.println("c");
else
System.out.println("d");
 
 }
}

Output is c

[Joe Borderi]

"if (obj3.equals(obj4)) //why is this false "

The statement evauates to false because Object.equals() (by default) returns the equality of the object references. Since obj3 and obj4 reference distinct objects in memory, the references themselves are not equal.

"if (obj1.equals(obj2)) //why is this true "

The Boolean.equals() method overrides the Object.equals(). According to the documentation:

public boolean equals(Object obj)
Returns true if and only if the argument is not null and is a Boolean object that represents the same boolean value as this object.

Overrides: equals in class Object

Parameters: obj - the object to compare with.

Returns: true if the Boolean objects represent the same value; false otherwise.