Passing mix of T and T[] to a Java varargs method
- by rfalke
Suppose you have a Java method
void foobar(int id, String ... args)
and want to pass both String arrays and Strings into the method. Like this
String arr1[]={"adas", "adasda"};
String arr2[]={"adas", "adasda"};
foobar(0, "adsa", "asdas");
foobar(1, arr1);
foobar(2, arr1, arr2);
foobar(3, arr1, "asdas", arr2);
In Python there is "*" for this. Is there some way better than such rather ugly helper method:
static String[] concat(Object... args) {
List<String> result = new ArrayList<String>();
for (Object arg : args) {
if (arg instanceof String) {
String s = (String) arg;
result.add(s);
} else if (arg.getClass().isArray() && arg.getClass().getComponentType().equals(String.class)) {
String arr[] = (String[]) arg;
for (String s : arr) {
result.add(s);
}
} else {
throw new RuntimeException();
}
}
return result.toArray(new String[result.size()]);
}
which allows
foobar(4, concat(arr1, "asdas", arr2));
