Java ArrayList of Doubles

Question

Is there a way to define an ArrayList with the double type  I tried both   ArrayList list   new ArrayList lt Double gt  1 38  2 56  4 3     and   ArrayList list   new ArrayList lt double gt  1 38  2 56  4 3     The first code showed that the constructor ArrayList lt Double gt  double  double  double  is undefined and the second code shows that dimensions are required after double

User · Answer

You can use Arrays asList to get some list  not necessarily ArrayList  and then use addAll   to add it to an ArrayList   new ArrayList lt Double gt    addAll Arrays asList 1 38L  2 56L  4 3L      If you re using Java6  or higher  you can also use the ArrayList constructor that takes another list   new ArrayList lt Double gt  Arrays asList 1 38L  2 56L  4 3L

User · Answer

Using guava  Doubles asList 1 2  5 6  10 1     or immutable list  ImmutableList of 1 2  5 6  10 1

User · Answer

Try this       List lt Double gt  l1  new ArrayList lt Double gt      l1 add 1 38    l1 add 2 56    l1 add 4 3

User · Answer

Try this   List lt Double gt  list   Arrays asList 1 38  2 56  4 3     which returns a fixed size list   If you need an expandable list  pass this result to the ArrayList constructor   List lt Double gt  list   new ArrayList lt  gt  Arrays asList 1 38  2 56  4 3

User · Answer

ArrayList list   new ArrayList lt Double gt  1 38  2 56  4 3     needs to be changed to   List lt Double gt  list   new ArrayList lt Double gt     list add 1 38   list add 2 56   list add 4 3

User · Answer

double   arr   new double    1 38  2 56  4 3    ArrayList lt Double gt  list   DoubleStream of  arr   boxed   collect      Collectors toCollection  new Supplier lt ArrayList lt Double gt  gt            public ArrayList lt Double gt  get             return  new ArrayList lt Double gt

User · Answer

Try this   ArrayList lt Double gt  numb  new ArrayList lt Double gt  Arrays asList 1 38  2 56  4 3

User · Answer

You are encountering a problem because you cannot construct the ArrayList and populate it at the same time  You either need to create it and then manually populate it as such   ArrayList list   new ArrayList lt Double gt     list add 1 38         Or  alternatively if it is more convenient for you  you can populate the ArrayList from a primitive array containing your values  For example   Double   array    1 38  2 56  4 3   ArrayList lt Double gt  list   new ArrayList lt Double gt  Arrays asList array

User · Answer

1   Unnecessarily complicated  is IMHO to create first an unmodifiable List before adding its elements to the ArrayList   2  The solution matches exact the question   Is there a way to define an ArrayList with the double type    double type   double   arr   new double    1 38  2 56  4 3     ArrayList   ArrayList lt Double gt  list   DoubleStream of  arr   boxed   collect      Collectors toCollection  new Supplier lt ArrayList lt Double gt  gt            public ArrayList lt Double gt  get             return  new ArrayList lt Double gt                               and this creates the same compact and fast compilation as its Java 1 8 short-form   ArrayList lt Double gt  list   DoubleStream of  arr   boxed   collect      Collectors toCollection  ArrayList  new

[java] Java ArrayList of Doubles

Examples related to java

Examples related to arraylist

Examples related to double