Hello everyone, I have a problem when doing substring. I need to get a string "0x" and the next two characters. If the string is "SDdfsReY0x33Erdfg" I need to get "0x33".
I guess it's very simple but I'm new to swift programming and I can not understand how the ranges work. Excuse the syntactic and spelling errors.
It's not super simple to work with Swift Strings.
You may need to:
let theString = "SDdfsReY0x33Erdfg"
if let rangeOfPrefix = theString.range(of: "0x") {
//`rangeOfPrefix.lowerBound` points '0' of "0x".
//`rangeOfPrefix.upperBound` points '3' next to "0x".
//In Swift 3, only the original String can calculate the indices to itself.
//(Assuming `offsetBy: 2` does not exceed the end of the String.)
let twoCharactersNext = theString.index(rangeOfPrefix.upperBound, offsetBy: 2)
let range = rangeOfPrefix.upperBound..<twoCharactersNext
let result = theString[range]
print(result) //-> 33
} else {
print("'0x' not found")
}You can write in Swift 3:
let output = "SDdfsReY0x33Erdfg"
let startingSequence = "0x"
startRange = output.range(of: startingSequence)
let char1 = output.character(at: startRange.location+2) // after 0x : get 51 (character 51)
let char2 = output.character(at: startRange.location+3) // after 0xn : get 51 (character 51)
then rebuild your 0x33
let s = String(UnicodeScalar(char1)!) + String(UnicodeScalar(char2)!)
It's not very clean, but that works on playground
It's not super simple to work with Swift Strings.
You may need to:
let theString = "SDdfsReY0x33Erdfg"
if let rangeOfPrefix = theString.range(of: "0x") {
//`rangeOfPrefix.lowerBound` points '0' of "0x".
//`rangeOfPrefix.upperBound` points '3' next to "0x".
//In Swift 3, only the original String can calculate the indices to itself.
//(Assuming `offsetBy: 2` does not exceed the end of the String.)
let twoCharactersNext = theString.index(rangeOfPrefix.upperBound, offsetBy: 2)
let range = rangeOfPrefix.upperBound..<twoCharactersNext
let result = theString[range]
print(result) //-> 33
} else {
print("'0x' not found")
}Thank you all!