Convert String to Lowercase in Swift

This tutorial will discuss how to write swift program to convert a string to lowercase.

A string is a sequence of characters for example, "RedCar". Or we can say, string are used to represent textual data. Swift support a String data type which is used to create a String type variable, or we can say to represent strings.

To convert the given string into lowercase Swift provide a in-built function named lowercased(). The lowercased() function is used to convert all the characters(either in lowercase or in uppercase or in both) of the given string into lowercase. This function does not take any parameter.

Below is a demonstration of the same ?

Input

Suppose our given input is ?

MyStr = "Hello! ToM"

Output

The desired output would be ?

Lowercased string = "hello! tom"

Syntax

Following is the syntax ?

stringName.lowercased()

Algorithm

Following is the algorithm ?

• Step 1 ? Create string with value

• Step 2 ? Convert the string into lowercase using lowercased() function ?

var lowerStr = String.lowercased()

• Step 3 ? Display the output

Convert a string to lowercase

Example

The following program shows how to convert a string to lowercase.

import Foundation
import Glibc

var String1 = "CaR iS In BlUe"
var String2 = "ITS RAINING TODAY"
var String3 = "i love icecreame"

// Convert to lowercase
var lowerStr1 = String1.lowercased()
var lowerStr2 = String2.lowercased()
var lowerStr3 = String3.lowercased()

print("Original String:", String1)
print("Lowercase String:", lowerStr1)

print("\nOriginal String:", String2)
print("Lowercase String:", lowerStr2)

print("\nOriginal String:", String3)
print("Lowercase String:", lowerStr3)

Output

Original String: CaR iS In BlUe
Lowercase String: car is in blue

Original String: ITS RAINING TODAY
Lowercase String: its raining today

Original String: i love icecreame
Lowercase String: i love icecreame

Here, in the above code, we have three strings named String1, String2, and String3. Now we convert them in lowercase using lowercased() function ?

var lowerStr1 = String1.lowercased() // Return car is in blue
var lowerStr2 = String2.lowercased() // Return its raining today
var lowerStr3 = String3.lowercased() // Return i love icecreame

Compare two strings using lowercased()

Example

The following program shows how to compare two strings using lowercased() function.

import Foundation
import Glibc

var String1 = "CaR iS REd"
var String2 = "car is RED"

// Comparing two strings
if (String1.lowercased() == String2.lowercased()){
   print("String1 and String2 are equal")
}
else{
   print("String1 and String2 are not equal")
}

Output

String1 and String2 are equal

Here, in the above code, we have two strings named: String1 and String2. Now we check if both the strings are equal or not. So we convert the given strings into lower case using lowercased() function and then using == we check both are equal or not ?

if (String1.lowercased() == String2.lowercased()){
   print("String1 and String2 are equal")
}
else{
   print("String1 and String2 are not equal")
}

Here both the strings are equal so we get an output: String1 and String2 are equal.