For 阿丑

No null in.scala

def doSomethingIfNoNull(name:String, password:String, other:String, doSomething: =>String): Option[String] = {
  for(n <- Option(name);
      p <- Option(password);
      o <- Option(other))
    yield(doSomething)
}

assert(doSomethingIfNoNull("abc", null, "cde", "Do something") == None)
assert(doSomethingIfNoNull(null, "abc", "cde", "Do something") == None)
assert(doSomethingIfNoNull("abc", "cde", null, "Do something") == None)
assert(doSomethingIfNoNull("abc", "cde", "fgh", "Do something") == Some("Do something"))