Array

An array is a data structure that stores a fixed number of elements of the same type in contiguous memory locations. Each element is identified by an index, usually starting from 0, so any element can be read or updated directly in constant time.

Arrays are simple and fast for accessing elements by position, but their size is fixed when they are created, and inserting or deleting an element in the middle requires shifting the elements after it.

int[] marks = {90, 75, 88};
System.out.println(marks[0]);     // 90
marks[1] = 80;                    // update by index
System.out.println(marks.length); // 3