How do I fill arrays in Java?

Question

I know how to do it normally, but I could swear that you could fill out out like a[0] = {0,0,0,0}; How do you do it that way? I did try Google, but I didn\'t get anything he

Answer 1

int[] a = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};

Answer 2

In Java-8 you can use IntStream to produce a stream of numbers that you want to repeat, and then convert it to array. This approach produces an expression suitable for use in an initializer:

int[] data = IntStream.generate(() -> value).limit(size).toArray();

Above, size and value are expressions that produce the number of items that you want tot repeat and the value being repeated.

Demo.

Answer 3

You can also do it as part of the declaration:

int[] a = new int[] {0, 0, 0, 0};

Answer 4

Arrays.fill(arrayName,value);

in java

int arrnum[] ={5,6,9,2,10};
for(int i=0;i<arrnum.length;i++){
  System.out.println(arrnum[i]+" ");
}
Arrays.fill(arrnum,0);
for(int i=0;i<arrnum.length;i++){
  System.out.println(arrnum[i]+" ");
}

Output

5 6 9 2 10
0 0 0 0 0

Answer 5

Check out the Arrays.fill methods.

int[] array = new int[4];
Arrays.fill(array, 0);

Answer 6

An array can be initialized by using the new Object {} syntax.

For example, an array of String can be declared by either:

String[] s = new String[] {"One", "Two", "Three"};
String[] s2 = {"One", "Two", "Three"};

Primitives can also be similarly initialized either by:

int[] i = new int[] {1, 2, 3};
int[] i2 = {1, 2, 3};

Or an array of some Object:

Point[] p = new Point[] {new Point(1, 1), new Point(2, 2)};

All the details about arrays in Java is written out in Chapter 10: Arrays in The Java Language Specifications, Third Edition.