The ternary operator in Java Linked list Search method

Question

i got a Syntax error on token "=", != expected in temp = temp.next

Here's the rest of the code

static boolean search(int xData) {

    Node temp = head; 

    while (temp != null) {
        return (temp.data == xData ) ? true : temp = temp.next;
    }

    return false;
}

Answer 1

You are trying to write something that can't be done with the conditional operator.

Instead:

if (temp.data == xData) return true;
temp = temp.next;

---

return (temp.data == xData )? true : temp = temp.next ;

Will always return. It is a return statement, after all. So, your loop would only ever iterate once.

You could have parenthesized the assignment:

return (temp.data == xData )? true : (temp = temp.next);

However:

• You're reassigning a local variable immediately before returning - what's the point?
• The type of the expression isn't Boolean, so it's not compatible with the return type of the method.

---

A nicer way to write this would be using a for loop:

for (Node temp = head; temp != null; temp = temp.next) {
  if (temp.data == xData) return true;
}
return false;