java - Strange Null pointer exception case: ternary conditional operator not working with string concatenation

Question

StringBuffer sb=null;

// Some more logic that conditionally assigns value to the StringBuffer

// Prints Value=null
System.out.println("Value="+sb);

// Throws NullPointerException
System.out.println("Value=" + sb != null ? sb.toString() : "Null");

The fix for this issue is encompassing the ternary operator in brackets:

// Works fine
System.out.println("Value=" + (sb != null ? sb.toString() : "Null"));

How is this possible?

Answer 1

A + has a higher precedence than a !=.

So you evalutate "(Value="+sb ) != null at first.