What are the differences between processing an array and a string when using loops for iteration?

When iterating over an array and a string in iOS (for example, in Swift), there are some differences related to data types and their structure.

• Array — a collection of elements of the same type. When iterating, you get each element as a separate object that can be worked with directly.

• String — a sequence of characters (Character). In Swift, a string is a collection of characters, but each character can be complex (for example, a composite emoji).

Example of iterating over an array:

let numbers = [1, 2, 3]
for number in numbers {
    print(number)
}

And over a string:

let text = "Hello"
for char in text {
    print(char)
}

The main difference is that when working with a string, it is important to consider that characters can be composite, and simple indexing may be inefficient or incorrect. An array has a fixed type and simpler indexing.