swift: issue in converting string to double, Swift uses the IEEE 754 standard for representing single- and double-precision floating point numbers, and if you assign let x = 8.7. then the Swift 4.2+ String to Double. iOS13 Navigation bar large titles not covering status bar. But that's not the end of the story, you may need to use the NumberFormatter (NSNumberFormatter) class to convert formatted numbers (1,000,000) or currency ($3.50) in your Swift … Double has a precision of at least 15 decimal digits, whereas the precision of Float can be as little as 6 decimal digits. Copy link. Xcode 11.3 • Swift 5.1 or later How to convert double to int in swift So I'm trying to figure out how I can get my program to lose the .0 after an integer when I don't need the any decimal places. Tip: We need to add as many zeros to 1 while multiplying and dividing, as many digits we want after the decimal point in our Double. print(String(format:"%a", x)) // 0x1.6666666666666p-1. Decimal to Double calculator. or when you use String format use 0 instead of 1: String(format: "%.0f", yourDoubleValue) this will just display your Double value with no decimal places, without converted it to int. Use a format string to round up to two decimal places and convert the double to a String: If you want to round up your last decimal place, you could do something like this (thanks Phoen1xUK): Updated to SWIFT 4 and the proper answer for the question, If you want to round up to 2 decimal places you should multiply with 100 then round it off and then divide by 100, (Swift 4.2 Xcode 11) These are the Float type which represents 32-bit floating point numbers with at least 6 decimal digits of precision and theDouble type which represents 64-bit floating point numbers at least 15 decimal … Published: 23 Dec 2016. Swift has these different numerical types because they store their data differently. share. Decimal … That is probably the most pragmatic thing to do, if you have the possibility. Updated to SWIFT 4 and the proper answer for the question If you want to round up to 2 decimal places you should multiply with 100 then round it off and then divide by 100 var x = 1.5657676754 var y = (x*100).rounded()/100 print(y) // 1.57 @IBOutlet weak var numberOfPeopleTextField: UITextField! Rounding Double in Swift. Simple to use Extension:-. if we need 3 digits after the decimal point, then we will multiply and divide by 1000. In some cases, however, the API is already a fact. You should use the new type initializers to convert between String and numeric types (Double, Float, Int). What we want to happen is to format the number so that two decimal places are visible, and helpfully SwiftUI comes with a specialized string interpolation that … How to enumerate an enum with String type? Decimal to Floating-Point Converter, It will convert a decimal number to its nearest single-precision and double- precision IEEE 754 binary floating-point number, using round-half-to-even rounding (the This is a little calculator intended to help you understand the IEEE 754 standard for floating-point computation. Type Safety and Type Inference Tuesday, October 11, 2016. iOS Swift. @IBOutlet weak var amountOfTurkeyLabel: UILabel! CC BY-SA 3.0. You might also use NumberFormatter although it always converts decimals to double first but that is not a problem in most cases. This example has been tested in xcode 8.2 using swift 3.0.1 on Macbook pro running macOS Sierra. How to get overall CPU usage in iOS Swift 4.x, Get CPU usage percentage of single iOS App in Swift 4.x, Get the currently connected WiFi informations in Swift 4.x, Check connection from iOS device to server by Swift 4.X, Get the server’s current time with Swift 4.X URLSession, Write a log text file on Disk use TextOutputStream in Swift 4 iOS. Swift string to double-precision. Updated to SWIFT 4 and the proper answer for the question. double input = 104.8695412 //For example long roundedInt = Math.round(input * 100); double result = (double) roundedInt/100; //result == 104.87 I personally like this version because it actually performs the rounding numerically, rather than by converting it … let double = 1.5 let string = double.description update Xcode 7.1 • Swift 2.1: Now Double is also convertible to String so you can simply use it as you wish: let double = 1.5 let doubleString = String(double) // "1.5" Swift 3 or later we can extend LosslessStringConvertible and make it generic. Int(yourDoubleValue) this will convert double to int. We might need to type cast the new variable back to Float or Double if we intent to use it further in any scenario which requires it to be of specific type. Get code examples like "make double to one decimal place swift" instantly right from your google search results with the Grepper Chrome Extension. Lets become friend :) What's your name & email? Your email address will not be published. If you are using JSONDecoder, you might prefer to use a Double rather than a Decimal as the decoded type even if you want the end result to be a Decimal, and do the conversion yourself, possibly via a String. The code for float to string with specific digits after decimals is: Here the %.2f tells the swift to make this number rounded to 2 decimal places. If you have an integer hiding inside a string, you can convertby using the integer’s constructor, like this: let myInt = Int(textField.text) As with other data types (Float and Double) you can also convert by using NSString: let myString = "556" let myInt = (myString as NSString).integerValue Rounding a Double in swift is quite simple and easy (tested up to swift 5.1). Consider using NumberFormatter for this purpose, it provides more flexibility if you want to print the percentage sign of the ratio or if you have things like currency and large numbers. GitHub Gist: instantly share code, notes, and snippets. You should use a floating-point type in Swift programs whenever you need a number with a decimal, such as 24.02 or 3.25. Float and Double. For example, both Double and Int take the same amount of memory to store their number, but Int only stores whole numbers whereas Double can store values after the decimal place. We simply need to use the round() function provided by swift. Rounding a Double in swift is quite simple and easy (tested up to swift 5.1). Contact. E.g. swift Show two decimal places Double. Web and Mobile Development Search This Blog. The reason Decimal exists is that it is able to exactly represent such numbers. Double has a precision of at least 15 decimal digits, whereas the precision of Float can be as little as 6 decimal digits. So, I thought would write about how to store money using Swift. The complete code of above example (for 2 digits after the decimal) will become: Importing UIKit is important as round function is part of it. The example below will demonstrate how to use this function effectively, while keeping your number still a Double (without changing the type). let a = String (42) // "42" let b = String (3.14) // "3.14" let c = " \(42), \(3.14) " // "42, 3.14". In the end we simply divided the whole round function output by 100, to bring back the value to the same one before we started (100/100 = 1). Double-precision, Floating-point numbers are numbers that have fractional parts (usually expressed with a decimal point). Learning by Sharing Swift Programing and more …. In Swift, there are two types of floating-point number, both of which are signed. stores in x an approximation of 0.7, because that number cannot. Solution that works in Swift 4. let double = 3.14 let decimal = Decimal(double) let doubleFromDecimal = NSDecimalNumber(decimal: decimal).doubleValue print(doubleFromDecimal) In situations where either type would be appropriate, Double is preferred. Adding to above answer if we want to format Double multiple times, we can use protocol extension of Double like below: Remove all non-numeric characters from a string in swift, Adding a view controller as a subview in another view controller. Swift 3.x. Then inside that function we simply multiplied our variable with 100. Floating-point types can represent a much wider range of values than integer types, and can store numbers that […] It doesn’t show up when you go via a string because the double-to-string code rounds the value. What you’re seeing here is the inexactness from Double being exactly propagated to Decimal. Share a link to this answer. In Swift 4 you get native String support for working with different numeric types (Float, Double, and Int). However that method results in type conversion of the new variable to string (not of the original one though). At the most basic level, creating a textual representation of a given number simply involves initializing a String with it, which can either be done directly, or by using a string literal:. There’s another method to limit a Float to certain digits after the decimal point too. Swift always chooses Double (rather than Float) when inferring the type of floating-point numbers.If you combine integer and floating-point literals in an expression, a type of Double … @IBOutlet weak va print (String (format:"%a", x)) // 0x1.6666666666666p-1. Solving the decimal problem. – Sulthan Aug 10 '17 at 10:06 decimal to string or string to decimal – Subhojit Mandal Aug 10 '17 at 10:26 How do I load a text file line by line into an array with Swift? let x : Double = 7/10. Now we want to round its value to 2 decimal places, we can achieve this by: What we have done here is that we used the round function. Download iWork for Free Officially (Pages, Keynote, numbers), Quit Cocoa App when Window Close using XCode Swift 3, Codeigniter 404 error on inner pages [solved], How to add javascript file in WordPress shortcode. If you want to round up to 2 decimal places you should multiply with 100 then round it off and then divide by 100. var x = 1.5657676754 var y = (x*100).rounded()/100 print(y) // 1.57 For example, let x : Double = 7/10. We might have acquired this variable dynamically too though. The appropriate floating-point type to use depends on the nature and range of values you need to work with in your code. From. Swift: round down double to x decimal places. How do I round up currentRatio to two decimal places? Finally, Swift offers two floating-point types which differ in size and in precision of their fractional component: Float (size: 32-bit, precision: ≥6 decimal digits) Double (size: 64-bit, precision: ≥15 decimal digits) #Numeric Literals. The "%f" format string means "a floating point number," but "%.2f" means "a floating-point number with two digits after the decimal point. This happens because we’ve placed a Double into a string, so Swift shows us the full value of that number. let x : Double = 7/10. When you use this initializer, Swift will automatically round the final digit as needed based on the following number. We will cover why this is even an issue in the first place and how you might address it in your code. The example below will demonstrate how to use this function effectively, while keeping your number still a Double (without changing the type). Double, are unable to exactly represent many decimal numbers. init(Double) Creates and initializes a decimal with the provided floating point value. be represented exactly as a Double. We simply need to use the round()function provided by swift.