Convert a string to lowercase or uppercase in Swift

In this Swift programming tutorial, you are going to learn how to convert a string to lowercase or uppercase.

In Swift, there are already in-built methods available that can help us to transform any string to lowercase or uppercase. One is the uppercased() and the other one is the lowercased().

Below is the syntax of the uppercased method:

string.uppercased()

And below is the syntax for the lowercased() method:

string.lowercased()

Convert to lowercase

Let’s see an example of transforming a string from uppercase to lowercase using the Swift lowercased() method:

let color = "YELLOW"
let transformed = color.lowercased()
print(transformed)

Output:

yellow

In the above program, we have a string color. We applied the lowercased() method to the string and store the new string in a constant transformed.

Convert to uppercase

Now below is an example of converting a string from lowercase to uppercase using the uppercased() method:

let color = "green"
let transformed = color.uppercased()
print(transformed)

Output:

GREEN

By Faruque Ahamed Mollick