let string = "aBcD"
string.uppercased() //ABCD
string.lowercased() //abcd
let emptyString = ""
emptyString.isEmpty //true
let string = "abcde"
string.count() //5
func replacingOccurrences(of target: String,
with replacement: String) -> String
var string = "abc12"
string = string.replacingOccurrences(of: "12", with: "de")
print(string) //abcde
정규식을 이용할 수 있다.
var new_id = "...!@BaT#*..y.abcdefghijklm"
new_id = new_id
//a-z0-9-_. 제외한 문자는 ""로 치환(^는 제외하라는 뜻)
.replacingOccurrences(of: "[^a-z0-9-_.]", with: "", options: .regularExpression)
//\.{2,} .이 2번이상 중복되면 .로 치환
.replacingOccurrences(of: #"\.{2,}"#, with: ".", options: .regularExpression)
"one" "two" "three"... "1~9"로 치환하기
var string = "one2three4"
let numDictionary = [
"zero" : "0",
"one": "1",
"two": "2",
"three": "3",
"four": "4",
"five": "5",
"six": "6",
"seven": "7",
"eight": "8",
"nine": "9"]
for (key, value) in numDictionary {
result = result.replacingOccurrences(of: key, with: value)
}
print(string) //"1234"
func trimmingCharacters(in set: CharacterSet) -> String
var string = ".abcd!"
string = string.trimmingCharacters(in: [".", "!"])
print(string) //abcd