Difference between Array and Set

Arrays and sets are both collection types in Swift, but there are some key difference between  Array and Set in terms of their characteristics and use cases.

Array:

1. Ordering:
   • Array: Elements in an array are ordered and have a specific index.
   • Accessing Elements: You access elements in an array using their index, which starts from zero.
2. Duplicates:
   • Array: Allows duplicate elements. You can have the same value appear multiple times in an array.
3. Syntax:
   • Array: Created using square brackets [] and can be mutable (var) or immutable (let).
4. Use Case:
   • Array: Use when the order of elements matters, and you need to access elements by index. Suitable for situations where elements have a meaningful order, and duplicates are allowed.

Example of an Array:

var fruits = ["Apple", "Banana", "Orange"]
print(fruits[0]) // Output: Apple

Set:

1. Ordering:
   • Set: Elements in a set are unordered. There is no guaranteed order of elements.
2. Duplicates:
   • Set: Does not allow duplicate elements. Every element in a set must be unique.
3. Syntax:
   • Set: Created using curly braces {}. Sets are always mutable.
4. Use Case:
   • Set: Use when the order of elements doesn’t matter, and you need to ensure that each element is unique. Suitable for situations where you want to perform operations like union, intersection, or checking membership efficiently.

Example of a Set:

var uniqueNumbers: Set<Int> = [1, 2, 3, 4, 5]
uniqueNumbers.insert(3) // Attempting to insert a duplicate element; no effect
print(uniqueNumbers) // Output: [5, 2, 3, 1, 4] (order is not guaranteed)

Common Operations:

Iteration:

Both arrays and sets support common operations like iteration, insertion, deletion, and checking for membership. The choice between them depends on the specific requirements of your use case.

for fruit in fruits {
    print(fruit)
}

for number in uniqueNumbers {
    print(number)
}

Insertion and Deletion:

fruits.append("Grapes") // Insertion in an array
uniqueNumbers.remove(2) // Deletion in a set

In summary, use an array when the order of elements matters, and duplicates are allowed, and use a set when you need uniqueness and the order of elements is not important.