Wednesday, February 8, 2017

Swift - Characters

A character in Swift is a single character String literal, addressed by the data type character. Take a look at the following example. It uses two Character constants −
import Cocoa

let char1: Character = "A"
let char2: Character = "B"

println("Value of char1 \(char1)")
println("Value of char2 \(char2)")
When the above code is compiled and executed, it produces the following result −
Value of char1 A
Value of char2 B
If you try to store more than one character in a Character type variable or constant, then Swift will not allow that. Try to type the following example in Swift Playground and you will get an error even before compilation.
import Cocoa

// Following is wrong in Swift
let char: Character = "AB"

println("Value of char \(char)")

Empty Character Variables

It is not possible to create an empty Character variable or constant which will have an empty value. The following syntax is not possible −
import Cocoa

// Following is wrong in Swift
let char1: Character = ""
var char2: Character = ""

println("Value of char1 \(char1)")
println("Value of char2 \(char2)")

Accessing Characters from Strings

As explained while discussing Swift's Strings, String represents a collection of Character values in a specified order. So we can access individual characters from the given String by iterating over that string with a for-in loop −
import Cocoa

for ch in "Hello" {
   println(ch)
}
When the above code is compiled and executed, it produces the following result −
H
e
l
l
o

Concatenating Strings with Characters

The following example demonstrates how a Swift's Character can be concatenated with Swift's String.
import Cocoa

var varA:String = "Hello "
let varB:Character = "G"

varA.append( varB )

println("Value of varC  =  \(varA)")
When the above code is compiled and executed, it produces the following result −
Value of varC Hello G

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