Java NullPointerException on conditional null check
I have a very basic method as a part of a binary search tree which simply returns True if the current binary node has a right child or False if that right child points to null.
public boolean hasRight(){
if(right.element != null){
return true;
}else{
return false;
}
However whenever I test this code, the moment that I know I will reach a node that does not have a right child, and would expect my code to just return False, java throws a NullPointerException at the line
if(right.element != null)
instead of returning False like I would expect it to.
Edit:
Fixed my code, simply had to check right itself being null before trying to get the element of right
public boolean hasRight(){
if(right != null){
return true;
}else{
return false;
}
}
Then right itself is null . Check for that first before attempting to access something on it.
if (right != null && right.element != null){
if right is null, you cannot access right.element() .
btw: Your method can be easier written as
hasRight(){
return right != null;
}
If you are getting a NullPointerException , then right should be null . So you could do this:
if(right != null && right.element != null){
return true;
}else{
return false;
}
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