The parameter 'foo' should not be assigned — what's the harm?

Question

Compare this method:

void doStuff(String val) {
    if (val == null) {
        val = DEFAULT_VALUE;
    }

    // lots of complex processing on val
}
         


        

Answer 1

In my experience, the use of null as a sentinel for the default parameter is more of an idiom in Python. In Java, you can just overload the method.

void doStuff() {
    doStuff(DEFAULT_VALUE);
}

void doStuff(final String val) {
    assert (val != null); // or whatever
    ...
}