Print a string from ArrayList of String[]?

Question

I have an ArrayList full of strings arrays that I built like this:

String[] words = new String[tokens.length];

I have three arrays like above in my ArrayList:

surroundingWords.add(words);
surroundingWords.add(words1);
surroundingWords.add(words2);

etc

Now if I want to print out the elements in the String arrays within surroundingWords... I can't. The closest I can get to displaying the contents of the String[] arrays is their addresses:

[Ljava.lang.String;@1888759
[Ljava.lang.String;@6e1408
[Ljava.lang.String;@e53108

I've tried a lot of different versions of what seems to be the same thing, the last try was:

for (int i = 0; i < surroudingWords.size(); i++) {
        String[] strings = surroundingWords.get(i);
        for (int j = 0; j < strings.length; j++) {
            System.out.print(strings[j] + " ");
        }
        System.out.println();
    }

I can't get past this because of incompatible types:

found   : java.lang.Object
required: java.lang.String[]
                String[] strings = surroundingWords.get(i);
                                                       ^

Help!

I've already tried the solutions here: Print and access List

score 10 · Answer 1 · answered Oct 06 '11 at 15:28

10

Try something like this

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

        lst.add(new String[] {"a", "b", "c"});
        lst.add(new String[] {"1", "2", "3"});
        lst.add(new String[] {"#", "@", "!"});

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

}

answered Oct 06 '11 at 15:28

Tarcísio Júnior

1,239
7
15

2

+1, this is the simplest an most "Java way" to go. The person asking the question should try and learn the behaviour of such java fundamentals as Object.toString() and Arrays / Collections helper classes – Shivan Dragon Oct 06 '11 at 15:36

score 4 · Accepted Answer · answered Oct 06 '11 at 15:24

4

Cast the Object into a String[]:

String[] strings = (String[]) surroundingWords.get(i);

or use a parameterized ArrayList:

ArrayList<String[]> surroundingWords = new ArrayList<String[]>();

Then you won't have to cast the return value from get().

answered Oct 06 '11 at 15:24

Poindexter

2,396
16
19

1

The ArrayList is the current "correct" way of doing it. – Kurtis Nusbaum Oct 06 '11 at 15:25
@Kurtis: Unless you're stuck in Pre-1.5 land – Poindexter Oct 06 '11 at 15:29
@Poindexter True, that's why I said **current** correct way :) – Kurtis Nusbaum Oct 06 '11 at 15:43

Print a string from ArrayList of String[]?

2 Answers2