How to convert variadic function arguments into collection such as Set or List

Question

Dear all,

In Java, we can use variadic function in the following way:

public Set packStrings(String...strings){
    for (String str : strings){
         //Do something on the str
    }

    //How to convert strings into a Set?
}

My question is, what is the type of "strings"? is it String[]? How to put the string(s) denoted by the "strings" into Java Collection, such as Set or List?

Please kindly advise.

Thanks & regards, William Choi

Answer 1

public Set<String> packStrings(String...strings){

    //Way 1 to create List
    List<String> strList = new ArrayList<String>();
    for (String str : strings){
         //adding to list
         strList.add(str);
    }
    //way 2 to create List
    List<String> strList = Arrays.asList(strings);
    //converting to set from List
    Set<String> setStr= new HashSet<String>(strList);
    return setStr;
}  

Have a look at this Doc

Answer 2

It's a string array, so you can do:

Arrays.asList(strings);