How to extract these integer values from ArrayList

Question

I am having a ArrayList<String> abc in which I am getting this value [64.3, 25.1, 44.3, 34.2, 6.4, 48.5, 35.5, 59.5, 54.6, 26.6, 11.2, 50.3, 25.1]

Now I want to extract the integer values from it such as 64,25,44,34,6,48,35,59,54,26,11,50,25 and put these values in an integer array int[] cab

How can I get this? How to remove the decimal and after decimal values from it?

@AndroidGeek Don't you think that would be a very important piece of information to add to the question? *(click "edit" link)* I mean, it looks like an `ArrayList` to anyone else, so saying that they are `String` objects is kinda important, you know. — Andreas, Feb 05 '16 at 07:23
use the iterator to extract the value from array list and cast to int — KVK, Feb 05 '16 at 07:24
why people have downvoted my question without reading it carefully. It''s not my mistake it's the readers mistake — Android Geek, Feb 05 '16 at 08:05

score 3 · Accepted Answer · answered Feb 05 '16 at 07:41

Here are three different (but similar) ways of doing it, depending on Java version and/or preferences:

ArrayList<String> abc = new ArrayList<>(Arrays.asList(
        "64.3", "25.1", "44.3", "34.2", "6.4", "48.5", "35.5",
        "59.5", "54.6", "26.6", "11.2", "50.3", "25.1" ));
System.out.println("abc = " + abc);

// Loop (all Java versions)
int[] cab1 = new int[abc.size()];
for (int i = 0; i < cab1.length; i++)
    cab1[i] = (int)Double.parseDouble(abc.get(i));
System.out.println("cab1 = " + Arrays.toString(cab1));

// Java 8 stream with lambda expression
int[] cab2 = abc.stream()
                .mapToInt(v -> (int)Double.parseDouble(v))
                .toArray();
System.out.println("cab2 = " + Arrays.toString(cab2));

// Java 8 stream with method references
int[] cab3 = abc.stream()
                .map(Double::valueOf)
                .mapToInt(Double::intValue)
                .toArray();
System.out.println("cab3 = " + Arrays.toString(cab3));

Output

abc = [64.3, 25.1, 44.3, 34.2, 6.4, 48.5, 35.5, 59.5, 54.6, 26.6, 11.2, 50.3, 25.1]
cab1 = [64, 25, 44, 34, 6, 48, 35, 59, 54, 26, 11, 50, 25]
cab2 = [64, 25, 44, 34, 6, 48, 35, 59, 54, 26, 11, 50, 25]
cab3 = [64, 25, 44, 34, 6, 48, 35, 59, 54, 26, 11, 50, 25]

Loop (all Java versions) it is giving me index out of bound exception — Android Geek, Feb 05 '16 at 07:54
@AndroidGeek I executed that code to generate that output, so you must have copied it incorrectly. — Andreas, Feb 05 '16 at 07:57
tried it again but still same error java.lang.ArrayIndexOutOfBoundsException: length=13; index=13 :( — Android Geek, Feb 05 '16 at 08:41

Derlin · Answer 2 · 2016-02-05T07:32:37.027

1

Simply iterate:

int[] cab = new int[abc.size()];
for(int i = 0; i < cab.length; i++){
    cab[i] = (int)Float.parseFloat(abc.get(i));
}

edited Feb 05 '16 at 07:32

answered Feb 05 '16 at 07:22

Derlin

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cannot cast java.lang.string to int – Android Geek Feb 05 '16 at 07:29
What is the type of your List `abc` ? – Derlin Feb 05 '16 at 07:29
I have mentioned it is string – Android Geek Feb 05 '16 at 07:31
not in the first version. Anyway, check the edited answer. – Derlin Feb 05 '16 at 07:32
java.lang.NumberFormatException: Invalid int: "64.3" – Android Geek Feb 05 '16 at 07:43
@AndroidGeek check my answer – KVK Feb 05 '16 at 07:47
My answer does not parse int but floats – Derlin Feb 05 '16 at 07:54

Sakam24 · Answer 3 · 2016-02-05T07:28:35.757

1

Try This :

Integer cab[] = new Integer[abc.size()];
cab= abc.toArray(cab);

//iterating array
for (Integer cabs: cab) {
System.out.println("cab= " + cabs);
}

edited Feb 05 '16 at 07:28

answered Feb 05 '16 at 07:27

Sakam24

121
5

score 0 · Answer 4 · edited Feb 05 '16 at 07:50

0

string to double

double to int

for(int i = 0 ; i < abc.size(); ++i) {
    tmp = Double.parseDouble(abc.get(i));
    cab[i] = (int)tmp;
    System.out.println(cab[i]);
}

edited Feb 05 '16 at 07:50

Prasad Khode

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answered Feb 05 '16 at 07:21

Steve YonG

80
7

score 0 · Answer 5 · answered Feb 05 '16 at 07:26

0

In Java 8:

int[] cab = abc.stream()
        .map(Double::valueOf)
        .mapToInt(Double::intValue)
        .toArray();

answered Feb 05 '16 at 07:26

shmosel

49,289
6
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it cannot resolve symbol stream() – Android Geek Feb 05 '16 at 07:32
@AndroidGeek Well, if you're using Android, you don't have Java 8. – shmosel Feb 05 '16 at 07:35

Dhinakaran Thennarasu · Answer 6 · 2016-02-05T07:56:03.080

0

ArrayList<Integer> newList = new ArrayList<Integer>(stringsList.size());
for (String myInt : strings){
    int intVal = (int)Double.parseDouble(myInt);
    newList.add(intVal);
}

where stringsList is your Arraylist

edited Feb 05 '16 at 07:56

answered Feb 05 '16 at 07:34

Dhinakaran Thennarasu

3,336
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score 0 · Answer 7 · answered Feb 05 '16 at 07:37

0

use this code

Iterator itr = al.iterator();
          while(itr.hasNext()) {

             String s1=itr.next().toString();
             Double d=new Double(s1);
             int s2=d.intValue();
             System.out.print(s2 + " ");
          }

answered Feb 05 '16 at 07:37

KVK

1,257
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Why not use a `for` loop? Why not use generics? `Double.parseDouble(s1)` would be better, since it doesn't create a wrapper object for the result. – Andreas Feb 05 '16 at 16:44

How to extract these integer values from ArrayList

7 Answers7