Swift-strings (string) usage detailed

The following is a summary of the properties and methods commonly used in string

1, determine whether it is empty: IsEmpty

123	varstr:Stringifstr.isEmpty{}

2, get the number of characters: countelements

12	let str = "hangge.com"println("\(countElements(str))个字符")

3, check if the string has a specific prefix/suffix: hasprefix/hassuffix

123	varstr = "hangge.com"ifstr.hasSuffix(".com"){}

4, you can also use "\ ()" In the string to wrap variables, constants

12	let name = "hangge.com"let msg = "欢迎来到 \(name)"

5, Case conversion:

Use the uppercasestring, LowerCaseString, capitalizedstring properties of a string to access a string of uppercase/lowercase/first letter capitals

12345

let str = "Welecome to Hangge.com"            var uppercase = str.uppercasestring  //welecome to hangge.com var lowercase = str.lowercasestring  //welecome to hangge.com var capitalized = str.capitalizedstring  //welecome to hangge.com

6, String intercept

(1) Convert string to NSString and intercept

12345

var str = "Welecome to hangge.com"        var fromStr = (str as NSString).substringFromIndex(5) //ome to hangge.comvar toStr = (str as NSString).substringToIndex(5)  //Welecvar rangeStr =  (str as NSString).substringWithRange(NSMakeRange(4,1)) //c

(2) direct call to the corresponding method of string (recommended)

123456789

var str = "Welecome to hangge.com"               let index = advance(str.startIndex, 5)let index2 = advance(str.endIndex, -5)var range = Range<String.Index>(start: index, end: index2)var fromStr = str.substringFromIndex(index)  //ome to hangge.comvar toStr = str.substringToIndex(index2)  //Welecome to hanggvar rangeStr = str.substringWithRange(range) //ome to hangg

Swift-strings (string) usage detailed