While iterating through an array, how can we get both the value and the index?

Sources & Resources

Main Source: 🔗 Ace the iOS Interview

Additional Sources:

Further Reading:

TL/DR

We can accomplish this easily with the help of the enumerated()function.

let title = ["Ace", "The", "iOS", "Interview"]

for (index, value) in title.enumerated() {
    print("Index: \(index), Value: \(value)")
}

// Index: 0, Value: Ace
// Index: 1, Value: The
// Index: 2, Value: iOS
// Index: 3, Value: Interview

The enumerated() function returns a sequence of pairs composed of the index and the value of each item in the array. Then, we can use tuple destructuring and aforloop to go through every element in the sequence.

A common mistake is to apply this function on a Dictionary.If you do this, the Dictionary will be treated as an array of tuples and your output will look like this:

let userInfo: [String: Any] = ["age": 25 , "gender": "male"]
for (index, value) in userInfo.enumerated() {
    print("Index: \(index), Value: \(value)")
}

// Index: 0, Value: (key: "age", value: 25)
// Index: 1, Value: (key: "gender", value: "male")