Hello I'm new to Swift and I'm building a calculator in Xcode. In my main storyboard I have a UIButton, UILabel and a UITextField that will get a number and by pressing the button, label's text should show the entered number + 5. In my app I need to convert a String variable to Int.
I tried the snippet below I didn't get any meaningful result.
var e = texti.text
let f: Int? = e.toInt()
let kashk = f * 2
label.text = "\(pashm)"
To make it clean and Swifty, I suggest this approach:
var string = "42" // here you would put your 'texti.text', assuming texti is for example UILabel
if let intVersion = Int(string) { // Swift 1.2: string.toInt()
let multiplied = 2 * intVersion
let multipliedString = "\(multiplied)"
// use the string as you wish, for example 'texti.text = multipliedString'
} else {
// handle the fact, that toInt() didn't yield an integer value
}
If you want to calculate with that new integer you have to unwrap it by putting an exclamation mark behind the variable name:
let stringnumber = "12"
let intnumber:Int? = Int(stringnumber)
print(intnumber!+3)
The result would be:
15
var string = "12"
var intVersion = string.toInt()
let intMultipied = intVersion! * 2
label.text= "\(intMultipied)"
Regarding how to convert a string to a integer:
var myString = "12" //Assign the value of your textfield
if let myInt = myString.toInt(){
//myInt is a integer with the value of "12"
} else {
//Do something, the text in the textfield is not a integer
}
The if let makes sure that your value can be casted to a integer.
.toInt() returns an optional Integer. If your string can be casted to a integer it will be, else it will return nil. The if let statement will only be casted if your string can be casted to a integer.
Since the new variable (constant to be exact) is a integer, you can make a new variable and add 5 to the value of your integer
var myString = "12" //Assign the value of your textfield
if let myInt = myString.toInt(){
//myInt is a integer with the value of “12”
let newInt = myInt + 5
myTextfield.text = "\(newInt)"
//The text of the textfield will be: "17" (12 + 5)
} else {
//Do something, the text in the textfield is not a integer
}
