NSString rangeOfString - Search for matching characters in a string

Type these codes in the playground:

let theString = "Hello World$$1234567890" as NSString

let range = theString.rangeOfString("$$")

//The result is:

//range.location = 11

//range.length = 2

let string1 = theString.substringToIndex(range.location)

let string2 = theString.substringFromIndex(range.location+range.length)

//The result is:

//string1 = "Hello World"

//string2 = "1234567890"