Comp Sci What is Instance, Empty Constructor in Java

[tking88]

What is Instance, Empty Constructor ... in Java

How come will return false I put in 2 same name it should return true ?

Teacher p1= new Teacher("Nelson"); 
System.out.println(p1); 
Teacher p2= new Teacher("Nelson"); 
System.out.println(p2); 

System.out.println(p1.equals(p2));

it print out

false

I do testing on below it give me ture how come the above not give me true

p1 = "Nelson";
p2 = "Nelson";
System.out.println(p1.equals(p2));

 

[silverfrost]

Without knowing much about Java (i.e. I could be wrong):

The equals method probably has a default implementation that just compares the two pointers and returns true or false depending on it.

so:

Teacher p1= new Teacher("Nelson"); 
System.out.println(p1); 
Teacher p2= new Teacher("Nelson"); 
System.out.println(p2);

p1.equals(p2)

actually calls (say)

bool object.equals(object p2)
{
  return p2==this;
}

Whereas... in your second example you had strings and string will have a specific equals method that compares strings as you expect.

So... write an equals that overrides the default one.

 

[tking88]

K I did something like this and all ok now it return the true compare value

public boolean equals(Object o)
{
System.out.println(o instanceof Moof);
System.out.println(((Moof)o).getMoofValue());
System.out.println(this.moofValue); //XXX
if ((o instanceof Moof) && (((Moof)o).getMoofValue() == this.moofValue))
{
return true;
}
else
{
return false;
}