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 Nu         


        

Answer 1

System.out.print() is implemented like that:

public void print(String s) {
        if (s == null) {
            s = "null";
        }
        write(s);
}

With sb = null, sb.toString() means null.toString() which leads to you NullPointerException