Reputation: 137

adding String array into ArrayList

I want to append a and b string arrays to arrayList. But "1.0" have to be "1" using with split. Split method returns String[] so arrayList add method does not work like this. Can you suggest any other way to doing this ?

String[] a = {"1.0", "2", "3"};
String[] b = {"2.3", "1.0","1"};

ArrayList<String> arrayList = new ArrayList<String>();

arrayList.add(a[0].split("."));

Upvotes: 2

Answers (7)

MiDhuN

Reputation: 232

This is working properly for me: arrayList.add(a[0].split("\\.")[0]);

Upvotes: 0

Kevin Lee

Reputation: 652

If you use Java 8,

String[] a = {"1.0", "2", "3"};

List<String> list = Arrays.stream(a).map(s -> s.split("\\.")[0]).collect(Collectors.toList());

// OR

List<String> list2 = Arrays.stream(a).map(s -> {
  int dotIndex = s.indexOf(".");
  return dotIndex < 0 ? s : s.substring(0, dotIndex);
}).collect(Collectors.toList());

Upvotes: 0

Android Killer

Reputation: 18509

Access first element of that array like this :

for (int i = 0; i < a.length; i++) {
    if (a[i].contains("."))
        arrayList.add(a[i].split("\\.")[0]);
    else
        arrayList.add(a[i]);
}

Upvotes: 1

TheLostMind

Reputation: 36304

Why split it?. Just use a replaceAll(), it will be more efficient as it won't create an array of Strings.

public static void main(String[] args) {
    String[] a = { "1.7", "2", "3" };
    List<String> arrayList = new ArrayList<String>();
    for (int i = 0; i < a.length; i++) {

        arrayList.add(a[i].replaceFirst("\\..*", "")); // escape the . (match it as a literal), then followed by anything any number of times.
    }
    System.out.println(arrayList);

}

O/P :
[1, 2, 3]

Upvotes: 0