Swift character
The character of Swift is a single character string literal, and the data type is Character .
The following example lists two character instances:
import Cocoa
let char1: Character = "A"
let char2: Character = "B"
print("The value of char1 is \(char1)")
print("The value of char2 is \(char2)")
The output of the above program execution is as follows:
The value of char1 is A
The value of char2 is B
If you want to Character if more characters are stored in the constant of type (character), the program execution will report an error, as shown below:
import Cocoa
// The following assignments in Swift will result in an error message
let char: Character = "AB"
print("Value of char \(char)")
The output of the above program execution is as follows:
error: cannot convert value of type 'String' to specified type 'Character'
let char: Character = "AB"
Null character variable
Cannot create empty in Swift Character type variable or constant:
import Cocoa
// The following assignments in Swift will result in an error message
let char1: Character = ""
var char2: Character = ""
print("The value of char1 \(char1)")
print("The value of char2 \(char2)")
The output of the above program execution is as follows:
error: cannot convert value of type 'String' to specified type 'Character'
let char1: Character = ""
^~
error: cannot convert value of type 'String' to specified type 'Character'
var char2: Character = ""
Traverse characters in a string
Swift’s String type represents a specific sequence Character a collection of type values. Each character value represents a Unicode characters.
In Swift 3 String need to pass through characters the property method to be called, which is available in Swift 4 through the String the object itself is called directly, for example:
In Swift 3:
import Cocoa
for ch in "Runoob".characters {
print(ch)
}
In Swift 4:
import Cocoa
for ch in "Runoob" {
print(ch)
}
The output of the above program execution is as follows:
R
u
n
o
o
b
String concatenation character
The following example demonstrates the use of the String of append() method to implement string concatenation characters:
import Cocoa
var varA:String = "Hello "
let varB:Character = "G"
varA.append( varB )
print("varC = \(varA)")
The output of the above program execution is as follows:
varC = Hello G