CODEWITHSUNDEEP
javaarraysarraylist
user962284
user962284

Reputation: 678

Java convert ArrayList<String[]> to String[][]

Do I have to loop through each element to convert ArrayList<String[]> to String[][] or is there a more efficient way?

Upvotes: 2

Views: 94

Answers (2)

Jeroen Vannevel
Jeroen Vannevel

Reputation: 44439

You can use .toArray(T[]) for this.

public static void main(String[] args) {
    List<String[]> l = new ArrayList<String[]>();

    String[] a = {"lala", "lolo"};
    String[] b = {"lili", "lulu"};
    l.add(a);
    l.add(b);

    String[][] r = new String[l.size()][];
    r = l.toArray(r);

    for(String[] s : r){
        System.out.println(Arrays.toString(s));
    }
}

Output:

[lala, lolo]
[lili, lulu]

Upvotes: 3

Sotirios Delimanolis
Sotirios Delimanolis

Reputation: 279890

Just get the contents as an array

List<String[]> list = new ArrayList<>();
...
String[][] array = list.toArray(new String[0][0]); // the size here is not important, the array is just an indication of the type to use

Upvotes: 8

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