Why is this line in findNode method of BST being marked "dead code"?

Question

I am attempting to implement a findNode method as part of a binary search tree in java.

public Node findNode(int findkey){
    Node tempNode5 = root;  

    while(findkey != tempNode5.key){
        if(tempNode5 != null){ // if the tempNode5 is not null
                               // and the node to be found hasn't been found yet
                               // then we will go to the leftChild or rightChild
                               // depending on the key
            if(findkey < tempNode5.key){
                tempNode5 = tempNode5.leftChild;
            }
            else tempNode5 = tempNode5.rightChild;
        }
        else return null; // this is the line that Eclipse marks "dead code"
                          // if the tempNode5 reaches null, it means the node to be found
                          // was not found in the BST, in which case I want to return null
    }
    return tempNode5; // if the while loop has exited and reached this line it means that 
                      // the node *has* been found, so I want to return it

}

Eclipse marks the line "else return null;" as dead code. I need to deal with the case that the node is not found in the tree, otherwise the while loop will run forever, so I need something similar that will return null when the node is not found.

Any help is appreciated :)

Answer 1

Have a look at these lines:

while(findkey != tempNode5.key){
        if(tempNode5 != null){

If tempNode5 is null, while will throw a NullPointerException and hence, any subsequent line won't be executed. So, control will only enter the while loop if tempNode5 is not null, making if..else redundant.