This question already has answers here:
How do I prevent my text from displaying Optional() in the Swift interpolation?
(3 answers)
Closed 5 years ago.
That's my code
let temperature = String(describing: Int(incomeTemp.text!))
celcjuszScore.text = "\(temperature)"
print(temperature)
Whent I am pushing a button, the result of print is "Optional(32)" (When I am writing 32 in incomeTemp). I would like to have "Optional" removed and only "32" should stay.
Just unwrap it.
if let temperature = Int(incomeTemp.text!) {
celcjuszScore.text = "\(temperature)"
print(temperature)
}
Remove the optional when converting text to number: Int(incomeTemp.text!) ?? 0.
Or solve the error explicitly:
if let temperature = Int(incomeTemp.text ?? "") {
celcjuszScore.text = "\(temperature)"
} else {
celcjuszScore.text = "Invalid temperature"
}
Related
This question already has an answer here:
Understanding the removeRange(_:) documentation
(1 answer)
Closed 2 years ago.
how can i remove character from string with rang. for example «banana» i want to remove only a from index (1..<3), i don’t want to remove the first and last character if they where «a»
i want from banana to bnna only removed the two midle.
the only thing i can do now is to remove the all “a”.
var charr = "a"
var somfruit = "banana"
var newString = ""
for i in somfruit{
if charr.contains(i) {
continue
}
newString.append(i)
}
print(newString)
In SWIFT 5 try:
var charr = "a"
var somfruit = "banana"
var newString = ""
let lower = somfruit.firstIndex(of: charr) + 1
let upper = somfruit.lastIndex(of: charr) - 1
newString = somfruit.replacingOccurrences(of: charr, with: '', option: nil, range: Range(lower, upper)
print(newString)
This is simplified. firstIndex and lastIndex returns Int? so you have to check they exist and they are not equals.
This question already has answers here:
Converting String to Int with Swift
(31 answers)
Closed 3 years ago.
I want to develop an application that can convert UITextField values into integer, float and double.
I am facing problem to convert String value into Integer.
Can anyone suggest the better way for conversion.
I have tried the following code but it didn't worked for Swift 4 and Xcode 10.
let result = txtTotakeInput.text
var newSTrings = Int(result!)
Thanks in advance.
A better and safer way to handle all three types Int, Float and Double will be
let result = txtTotakeInput.text
if let intVal = Int(result ?? "") {
// Use interger
}
else if let floatVal = Float(result ?? "") {
// Use float
}
else if let doubleVal = Double(result ?? "") {
// Use double
}
else {
print("User has not entered integer, float or double")
}
Int.init(_ string) returns an optional, since its possible that the string is not an integer. So you can either make newStrings optional like var newSTrings = result.flatMap(Int.init) or nil coalesce it to zero or some other default var newSTrings = result.flatMap(Int.init) ?? 0
This question already has answers here:
Swift find all occurrences of a substring
(7 answers)
Closed 5 years ago.
Swift 4 apparently has introduced a lot of new changes to String. I'm wondering if there is now a built-in method for finding all instances of a substring within a String.
Here's the kind of thing I'm looking for:
let searchSentence = "hello world, hello"
let wordToMatch = "hello"
let matchingIndexArray = searchSentence.indices(of: "wordToMatch")
'matchingIndexArray' would then be [0, 13]
import Foundation
let searchSentence = "hello world, hello"
var searchRange = searchSentence.startIndex..<searchSentence.endIndex
var ranges: [Range<String.Index>] = []
let searchTerm = "hello"
while let range = searchSentence.range(of: searchTerm, range: searchRange) {
ranges.append(range)
searchRange = range.upperBound..<searchRange.upperBound
}
print(ranges.map { "(\(searchSentence.distance(from: searchSentence.startIndex, to: $0.lowerBound)), \(searchSentence.distance(from: searchSentence.startIndex, to: $0.upperBound)))" })
outputs:
["(0, 5)", "(13, 18)"]
This question already has an answer here:
Error "{ expected after if statement"
(1 answer)
Closed 6 years ago.
Pardon me for beginner's question, Why this code got complained about { expected after if, the braces are already there
var years = Int(edtYears.text!)
if years !=nil {
//do something
}else {
//...
}
Thanks
You need to add space between both side of condition like if years != nil { or you can also write without space but the both side if years!=nil {
var years = Int("")
if years != nil {
//do something
}else {
//...
}
Never do like this. Make sure you do optional chaining otherwise you will surely get a crash.
if let text = edtYears.text, let convertToInt = Int(text){
print("Int \(convertToInt)")
}else{
print("Cannot convert")
}
This question already has answers here:
Adding Thousand Separator to Int in Swift
(7 answers)
Closed 7 years ago.
My English is not enough to search the question. So, I have to write here. My integer is 600000000 for ex. I want to convert it like this: 600,000,000. How do I do this?
extension Int {
struct Number {
static let formatter = NSNumberFormatter()
}
var addThousandSeparator:String {
Number.formatter.groupingSeparator = "."
Number.formatter.numberStyle = NSNumberFormatterStyle.DecimalStyle
return Number.formatter.stringFromNumber(self)!
}
}
let myInteger = 600000000
let myIntegerString = myInteger.addThousandSeparator // "600.000.000"