Array Methods (Python & Java)

The array objects support the following attributes and methods.

Array Methods (Python)

1. a.typecode — the typecode character used to create the array.
2. a.itemsize — size, in bytes, of items stored in the array.
3. a.append(x) — appends item x to the end of the array.
4. a.buffer_info() — returns the memory location and length of the buffer used to store the array.
5. a.byteswap() — swaps the byte order of each item. Used for writing to a machine or file with a different byte order.
6. a.count(x) — returns the number of occurrences of x in a.
7. a.extend(b) — appends any iterable, b, to the end of array a.
8. a.frombytes(s) — appends items from a string, s, as an array of machine values.
9. a.fromfile(f, n) — reads n items, as machine values, from a file object f, and appends them to a. Raises an EOFError if there are fewer than n items available.
10. a.fromlist(l) — appends items from list l.
11. a.fromunicode(s) — extends a with unicode string s. Array a must be of type u or else ValueError is raised.
12. a.index(x) — returns the first (smallest) index of item x.
13. a.insert(i, x) — inserts item x before index i.
14. a.pop([i]) — removes and returns the item at index i. Defaults to the last item (i = -1) if not specified.
15. a.remove(x) — removes the first occurrence of item x.
16. a.reverse() — reverses the order of items.
17. a.tobytes() — converts the array to machine values and returns the bytes representation.
18. a.tofile(f) — writes all items, as machine values, to file object f.
19. a.tolist() — converts the array to a list.
20. a.tounicode() — converts an array to a unicode string. The array type must be u or else a ValueError is raised.

Implementing an Array in Java

import java.util.Arrays;

public class Main {
  public static void main(String[] args) {
    // Declaring an array
    int arr[] = {8, 5, 3, 10, 2, 1, 15, 20};

    // Sorting the array
    Arrays.sort(arr);

    // Taking an element to search
    int ele = 15;

    // Using binarySearch() method to search "ele"
    System.out.println(
      ele + " presents at the index = " +
      Arrays.binarySearch(arr, ele));
  }
}