Doubt about a null value assigned to a String variable

Question

Hi,
I have a doubt about a behavior when assigning a null value to a string variable and then seeing the output, the code is the next one:
public static void main(String[] args) {
        String total = null;
        System.out.println(total);
        total = total+"one";
        System.out.println(total);
}the doubt comes when i see the output, the output i get is this:
null
nulloneA variable with null value means it does not contains a reference to an object in memory, so the question is why the null is printed when i concatenate the total variable which has a null value with the string "one".
Is the null value converted to string ??
Please clarify
Regards and thanks!
Carlos

Answer 1

null is a keyword to inform compiler that the reference contain nothingNo. 'null' is not a keyword, it is a literal. Beyond that the compiler doesn't care. It has a runtime value as well.
total contains null value means it does not have memory,No, it means it refers to nothing, as opposed to referring to an object.
for representation purpose it contain "null"No. println(String) has special behaviour if the argument is null. This is documented and has already been described above. Your handwaving about 'for representation purpose' is meaningless. The compiler and the JVM don't know the purpose of the code.
e.g. this keyword shows a hash value instead of memory addressNo it doesn't: it depends entirely on the actual class of the object referred to by 'this', and specifically what its toString() method does.
similarly "total" maps null as a literal.Completely meaningless. "total" doesn't 'map' anything, it is just a literal. The behaviour you describe is a property of the string concatenation operator, not of string literals.
I hope you can understand this.Nobody could understand it. It is compete nonsense. The correct answer has already been given. Please read the thread before you contribute.