Java Arrays

• Linear data structure that is used to store multiple values of the same datatype

  int[] arr = {1,2,3,4};
  System.out.println("Array length", arr.length);
  

int arr1 = java.util.stream.IntStream.range(1,5).toArray(); // exclusive of upper limit

int arr2 = java.util.stream.IntStream.rangeClosed(1,4).toArray(); // inclusive

int[] arr3 = java.util.stream.IntStream.of(1,2,3,4).toArray();

Multidimensional arrays

int[][] arr;

arr = new int[1][3]

int[][] = new int[n][m];

Array Class

Arrays.equals(arr1, arr2);
Arrays.sort(arr);
Arrays.fill(arr, value);
Arrays.copyOf(arr, newLength);

Returning Arrays from Methods

public int[] createArray() {
    return int[]{1,2,3};
}

Efficient copying of arrays

int[] src = {1,2,3};
int[] dest = new int[3];

System.arraycopy(src, 0 dest, 0, src.length);

Example: Bubble Sort

public static void bubbleSort(int[] array) {
    int n = arr.length;
    for(int i = 0; i < n - 1; i++) {
        for(int j = 0; j < n-i-1; j++) {
            if(arr[j] > arr[j+1]) {
                int temp = arr[j];
                arr[j] = arr[j+1];
                arr[j+1] = temp;
            }
        }
    }
}