Help understand a method

[JultomteN]

    public void close() 
    { 
        for(Lot lot : lots) { 
            System.out.println(lot.getNumber() + ": " + 
                               lot.getDescription()); 
            Bid highestBid = lot.getHighestBid(); 
            if(highestBid != null) { 
                System.out.println("    Highest bidder: " +  
                                   highestBid.getBidder().getName());
                System.out.println("    Bid: " +  
                                   highestBid.getValue()); 
            } 
            else { 
                System.out.println("    Not sold"); 
            } 
        } 
    }

It's one part of this method that i don't understand,

and that is:

Bid highestBid = lot.getHighestBid();

Why do you set a local variable of the type Bid as the method lot.getHighestBid(), why don't you just use lot.getHighestBid() directly? I've tried it and i doesn't work so something wrong is it, but I can't just understand why.

[JosAH]

You can do as you described, but then you have to get that highest bidder over and over again (extra method calls). In this code snippet the author decided to get the highest bidder once by using that method and store it in a local variable. It's a matter of taste and it's completely assuming that the method itself is 'idem potent', i.e. it returns the same value over and over again.

kind regards,

Jos