Swift Character, Operations on Character

In Swift, Character is a value type that represents a single extended grapheme cluster, which is a sequence of one or more Unicode scalars that combine to produce a single human-readable character. Operations on Character can be useful when working with user inputs, data processing, or data validation.

Creating a Character

A Character can be created from a single character literal, which is a single character enclosed in single quotes:

1let exclamationMark: Character = "!"

It can also be created from a string by using the first property of the string, which returns the first character:

1let hello = "hello"
2let firstCharacter = hello.first // returns Optional("h")

Note that the first property returns an optional value since the string may be empty.

String Interpolation with Character

Character values can be interpolated into strings by using the \() syntax:

1let letter: Character = "a"
2let message = "The first letter of the alphabet is \(letter)."

Operations on Character

Counting Characters

The count property of a String returns the number of characters in the string. Since Character represents a single character, the count property of a Character always returns 1:

1let exclamationMark: Character = "!"
2let count = exclamationMark.count // returns 1

Checking for Equality

You can use the == operator to check if two Character values are equal:

1let a: Character = "a"
2let b: Character = "b"
3if a == b {
4    print("a and b are the same character.")
5} else {
6    print("a and b are different characters.")
7}

Converting to a String

A Character can be converted to a String by using the String initializer:

1let exclamationMark: Character = "!"
2let string = String(exclamationMark)

Checking for Digit

You can check if a Character represents a digit using the isDigit property:

1let digit: Character = "5"
2let nonDigit: Character = "a"
3if digit.isDigit {
4    print("\(digit) is a digit.")
5}
6if !nonDigit.isDigit {
7    print("\(nonDigit) is not a digit.")
8}

Checking for Letter

You can check if a Character represents a letter using the isLetter property:

1let letter: Character = "a"
2let nonLetter: Character = "5"
3if letter.isLetter {
4    print("\(letter) is a letter.")
5}
6if !nonLetter.isLetter {
7    print("\(nonLetter) is not a letter.")
8}

Checking for Whitespace

You can check if a Character represents whitespace using the isWhitespace property:

1let whitespace: Character = " "
2let nonWhitespace: Character = "a"
3if whitespace.isWhitespace {
4    print("\(whitespace) is whitespace.")
5}
6if !nonWhitespace.isWhitespace {
7    print("\(nonWhitespace) is not whitespace.")
8}