Swift Basics - Strings

Using strings:

Declaring a multiple line string variable:

var multiLineString = """

ABCD

EFGHI

"""

You can add quotes in multiple line variables:

var heSaid = """

He said,"Hello."

"""

To go through each character in a string:

for char in nameOfString.characters

{

 print(char)

}  

OR

nameOfString.map

{

 print($0)

}

Concatenate 2 strings:

var c = a + b

a += b

b = "Hello \(a)"

You cannot add another part of a string to a constant.

Print in lowercase:

a.lowercased()

b.uppercased()

Replace an occurrence of a string with another:

nameOfString.replacingOccurences(of: "boy", with: "girl")

Working with substrings
Getting a string between the third and eighth character of a string:

let starting = nameOfString.index(nameOfString.startIndex, offsetBy: 2)

let ending = nameOfString.index(nameOfString.startIndex, offsetBy: 7)

let theSubString = nameOfString[starting ..< ending]

let newString = String(theSubString)

If you have a string and you wish to get the first 3 characters:

nameOfString.substring(to: starting)

You wish to extract out the last 4 characters:

nameOfString.substring(from: ending)

Getting the first letter of the string:

nameOfString.first

Getting the last letter of the string:

nameOfString.last

Getting the number of letters in a string:

var length = nameOfString.count