adding String array into ArrayList

Question

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("."));

Answer 1

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

Answer 2

应如下

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

Answer 3

Split method returns an array. You have to access to his position to get the number.

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

You can also use substring method:

arrayList.add(a[0].substring(0, 1));

Answer 4

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]);
}

Answer 5

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]

Answer 6

这对我来说是正常的： arrayList.add(a[0].split("\\\\.")[0]);

Answer 7

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());