I am using Xcode playground to downcast in swift. Typecasting would normally allow me to convert a type to derived type using As operator in swift. But it gives me error while i try to typecast var a as Double,String. Thanks in advance!!
var a = 1
var b = a as Int
var c = a as Double
var d = a as String
You cannot cast it to each other because they do not relate. You can only cast types that are related like UILabel and UIView or [AnyObject] and [String]. Casting an Int to a Double would be like trying to cast a CGPoint to a CGSize
So to change for example an Int to a Double you have to make a new Double of that Int by doing Double(Int).
This applies to all numeric types like UInt Int64 Float CGFloat etc.
Try this:
var a = 1
var b = Int(a)
var c = Double(a)
var d = String(a)
Cast as Int works, because a is Int
You should do it like this:
var c = Double(a)
var d = toString(a) //or String(a)
Related
I want to assign two variables to integer and decimal parts on double.
how to do it?
One way would be
int x = abc.toInt()
int y = int.tryParse(abc.toString().split('.')[1]);
final double abc = 1.4;
int a = int.parse(abc.toString().split(".")[0]);
int b = int.parse(abc.toString().split(".")[1]);
Try this out, it should work fine
I'm trying to convert an integer variable
var int counter = 0;
into a string variable
var String $counter = "0";
I searched but I only found something like
var myInt = int.parse('12345');
that doesn't work with
var myInt = int.parse(counter);
Use toString and/or toRadixString
int intValue = 1;
String stringValue = intValue.toString();
String hexValue = intValue.toRadixString(16);
or, as in the commment
String anotherValue = 'the value is $intValue';
// String to int
String s = "45";
int i = int.parse(s);
// int to String
int j = 45;
String t = "$j";
// If the latter one looks weird, look into string interpolation on https://dart.dev
You can use the .toString() function in the int class.
int age = 23;
String tempAge = age.toString();
then you can simply covert integers to the Strings.
Hello I have string "(with float value)"
let floatstring : String = "23.24"
print(floatstring)
I want to convert float String to Int.
Thank you !
Option 1
let intNum = Int(Float(floatstring)!)
Option 2
if floatstring.rangeOfString(".") != nil {
let i = Int(floatstring.componentsSeparatedByString(".").first!)
print(i)
}
It should work like this:
http://swiftlang.ng.bluemix.net/#/repl/57bd6566b36620d114f80313
let floatstring : String = "23.24"
print(Int(Float(floatstring)!))
You can cast the String to a Float and then to an Int.
if let floatValue = Float(floatString) {
if let intValue = Int(floatValue) {
print(intValue) //that is your Int
}
}
If it does not print anything then the string is not a 'floatString'.
Btw you can simply find the answer by combining the answers to these Questions.
Stackoverflow: String to Int
Stackoverflow: Casting Float to Int
1.For Swift 2.0
let intValue=int(float(floatString))
2.For Older version of Swift
let floatValue = (floatString.text as NSString).floatValue
let intValue:Int? = Int(floatValue)
3.For objective-C
floatValue = [floatString floatValue];
int intValue:Int = (int) floatValue;
Try This
let floatValue = "23.24".floatValue // first convert string to float
let intValue:Int? = Int(floatValue) // then convert float to int
print(intValue!)
I want to multiply a text field by a multiplier, but I keep getting the error below. Can anyone help? Using Swift.
Binary operator '*' cannot be applied to operands of type 'Int?' and 'Double'
var Number1 = Int(weight.text!)
let lidocainemult = (1.5)
var lidoresult = Number1 * lidocainemult
lidocaine.text = NSString(format:"%d",lidoresult)as String;
You're going to have to convert your variables into the same type first. Here Double would make the most sense, since there would be no loss of information (unlike rounding to produce an Int!).
var Number1 = Double(weight.text!)
let lidocainemult = (1.5)
var lidoresult = Number1 * lidocainemult
lidocaine.text = NSString(format:"%d",lidoresult)as String;
You must convert Number1 to a Double, the operands must be of same type.
var Number1 = Double(weight.text!)
I've looked at the answers for converting int's to floats and other similar answers but they don't do exactly what I want.
I'm trying to create a basic program that takes a number does some different calculations onto it and the results of those calculations are added together at the end.
For one of those calculations I created a segmented controller with the 3 different values below
var myValues: [Double] = [0.00, 1.00, 1.50]
var myValue = [myValuesSegmentedController.selectedSegmentIndex]
then when one of those values is picked, it's added to the final value. All the values added together are Doubles to 2 decimal places.
var totalAmount = valueA + valueB + valueC + myValue
the problem I'm having is that swift won't let me add "myValue" to those final calculations. It gives me the error:
Swift Compiler Error. Cannot invoke '+' with an argument list of type '($T7, #lvalue [int])'
What do I need to do to change that value to a Double? Or what can I do to get a similar result?
You can cast it with Double() like this
var totalAmount = valueA + valueB + valueC + Double(myValue)
The problem is you are trying to add an array instead of an Int, so You don't even need to convert anything, considering that all of your values are already Doubles and your index actually has to be an Int. So
let myValues = [0.00, 1.00, 1.50]
let myValue = [myValuesSegmentedController.selectedSegmentIndex] // your mistake is here, you are creating one array of integers with only one element(your index)
The correct would be something like these:
let myValues = [0.00, 1.00, 1.50]
let totalAmount = myValues.reduce(0, combine: +) + myValues[myValuesSegmentedController.selectedSegmentIndex]
Put this in a playground:
var myValues: [Double] = [0.00, 1.00, 1.50]
let valueA = 1
let valueB = 2
let valueC = 3
var totalAmount = Double(valueA + valueB + valueC) + myValues[2]
println(totalAmount) //output is 7.5
valueA/B/C are all inferred to be Int.
totalAmount is inferred to be a Double
To convert a float to an integer in Swift. Basic casting like this does not work because these vars are not primitives, unlike floats and ints in Objective-C:
var float:Float = 2.2
var integer:Int = float as Float