How to initialize all the elements of an array to any specific value in java

Question

In C/C++ we have memset() function which can fulfill my wish but in Java how can i initialize all the elements to a specific value? Wh

Answer 1

Using Java 8, you can simply use ncopies of Collections class:

Object[] arrays = Collections.nCopies(size, object).stream().toArray();

In your case it will be:

Integer[] arrays = Collections.nCopies(10, Integer.valueOf(1)).stream().toArray(Integer[]::new);
.

Here is a detailed answer of a similar case of yours.

Answer 2

You could do this if it's short:

int[] array = {-1,-1,-1,-1,-1,-1,-1,-1,-1,-1};

but that gets bad for more than just a few.

Easier would be a for loop:

  int[] myArray = new int[10];
  for (int i = 0; i < array.length; i++)
       myArray[i] = -1;

Edit: I also like the Arrays.fill() option other people have mentioned.

Answer 3

It is also possible with Java 8 streams:

int[] a = IntStream.generate(() -> value).limit(count).toArray();

Probably, not the most efficient way to do the job, however.

Answer 4

java.util.Arrays.fill()

Answer 5

For Lists you can use

Collections.fill(arrayList, "-")

Answer 6

If it's a primitive type, you can use Arrays.fill():

Arrays.fill(array, -1);

[Incidentally, memset in C or C++ is only of any real use for arrays of char.]