How to Pass an Arraylist to a Varargs Method Parameter

How to pass an ArrayList to a varargs method parameter?

Source article: Passing a list as an argument to a vararg method

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Use the toArray(T[] arr) method.

.getMap(locations.toArray(new WorldLocation[0]))

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Here's a complete example:

public static void method(String... strs) {
    for (String s : strs)
        System.out.println(s);
}

...
    List<String> strs = new ArrayList<String>();
    strs.add("hello");
    strs.add("world");
    
    method(strs.toArray(new String[0]));
    //     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
...

How do I pass an ArrayList to a method expecting a vararg (Object...)?

Convert your ArrayList into an Array of type object.

ClassName.foo("something", "something", arrayList.toArray());

How to pass a list as parameter for varargs?

Use the List#toArray(T[]) method to create an array from the list, and pass it.

takeParams(strings.toArray(new String[strings.size()]));

How to convert List to varargs object in Java 8

Convert the List<String> into an array String[]:

// Java-8(tag in question)
List<Users> users = findByNames(names.toArray(new String[0]));
// Java-11
List<Users> users = findByNames(names.toArray(String[]::new));

Passing a List in as varargs

Just pass things.toArray(new Thing[things.size()]).

Can I pass an array as arguments to a method with variable arguments in Java?

The underlying type of a variadic method function(Object... args) is function(Object[] args). Sun added varargs in this manner to preserve backwards compatibility.

So you should just be able to prepend extraVar to args and call String.format(format, args).

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