Discussion
What will be the output of the program?
public class Trial77
{
Trial77()
{
String a = null;
System.out.println(String.valueOf(a));
System.out.println(a + "");
}
public static void main(String[] args)
{
new Trial77();
}
}
Answer: A
String.valueOf checks for null and returns the text null rather than throwing, and concatenation applies the same conversion. So both lines print the four characters null. It is calling a method ON the null reference that fails, which neither line does.
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