What is the use of type casting 'null' to any reference type in JAVA?

Question

Is there anything which can be achieved by type casting null to say String ref type?

String s = null;
String t = (String) null;

Both does the same thing.

sysout(s) displays null

sysout((String)null) displays null

To distinguish between overloads. – shmosel Jul 03 '16 at 10:50 — shmosel, Jul 03 '16 at 10:50

score 11 · Accepted Answer · answered Jul 03 '16 at 10:50

Suppose you have overloaded methods that take a single parameter, and you want to call one of them and pass null to it.

public void method1 (String param) {}

public void method1 (StringBuilder param) {}

If you make a call

method1 (null);

the code won't pass compilation, since both methods accept a null reference, and the compiler has no preference between the two overloads.

If you call

method1 ((String) null);

the first method will be called.

If you call

method1 ((StringBuilder) null);

the second method will be called.

1 Answers1