Swift decimal precision. Jul 23, 2023 · I thought the whole point of the Decimal type was arbitrary precision arithmetic. Nov 12, 2024 · In Swift, the "Double" data type is essential for handling floating-point arithmetic with precision and efficiency. Unlike floating-point types such as Double or Float, Decimal avoids binary representation issues inherent in those types, ensuring exact values. (Or rather I thought that Decimal supported arbitrary precision as well as supporting base-10 arithmetic. However I'm having precision issues that do not reproduce when using NSDecimalNumber. 5, or 9. 99, Swift uses floating-point numbers, usually of type Double. 14, 0. Learn how to properly initialize the `Decimal` type in Swift to avoid precision loss when dealing with decimal numbers. Nov 21, 2021 · Given these and other issues (eg JSONDecoder doesn't decode JSON to Decimal reliably), it seems Decimal is creating more problems than it solves. Example 1 To specify the number of decimal places for a floating-point number, you can use the %. nf format specifier, where n is the number of decimal places. Sep 12, 2019 · How to obtain precision of two numbers after the decimal point but without rounding the double in SWIFT [duplicate] Asked 5 years, 5 months ago Modified 5 years, 5 months ago Viewed 773 times Jan 21, 2016 · 40 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 Jan 3, 2023 · In Swift, you can use precision specifiers to specify the number of decimal places or the number of characters to be displayed in a string. 3 Feb 22, 2022 · I have an precision issue when dealing with currency input using Decimal type. The issue is with the formatter. Oct 1, 2021 · That’s short for “double-precision floating-point number”, which I realize is quite a strange name – the way we’ve handled floating-point numbers has changed a lot over the years, and although Swift does a good job of simplifying this you might sometimes meet some older code that is more complex. Jan 16, 2015 · Can you precise (pun intended :) what you mean by the precision of a floating point number? From your answer I assume that you are talking about decimal precision. 6789, you might only want to show two digits after the decimal place. 123 cannot be represented exactly, it would be more like 0. I've tried a number of approaches but they all run into the same issue. It's documentation says only A structure representing a base-10 number. Decimals are used for things like ratings, percentages, and measurements. But Float and Double use a binary representation, which means that a number like 0. It is available from GitHub here. 12299999999999999822. , Jul 14, 2015 · I'm trying to separate the decimal and integer parts of a double in swift. ) However, Oct 6, 2025 · Handling Precision and Rounding When working with financial or scientific data, controlling decimal places and rounding behavior is crucial. Jun 1, 2019 · Swift's string interpolation makes it easy to put floating-point numbers into a string, but it lacks the ability to specify precision. This is the minimum reproducible code in playground: let formatter = NumberFormatter() Nov 16, 2017 · According to the docs here, Swift 3/4 Decimal type is a representation in base 10 bridged to NSDecimalNumber. Swift's Decimal type, often bridged through NSDecimalNumber, provides robust options for this. ---This video is based on the question Dec 10, 2020 · There is a type in the Foundation module called Decimal. For example, if a number is 45. Martin R – Martin R 2015-01-16 12:15:31 +00:00 CommentedJan 16 Jun 5, 2014 · FWIW I needed to convert a Float to 2 decimal places and used var valueAsString = String (format: "0. Does anyone know if there are any plans to add an arbitrary precision decimal type like BigDecimal to Swift (and fix JSONDecoder and JSONEncoder if necessary)? Nov 22, 2025 · Swift's Decimal struct is your go-to for financial and currency calculations where precision is paramount. The double data type offers a higher precision than the standard "Float" type, making it ideal for calculations requiring more significant decimal digits or operations with floating point values. 2f", value) and it worked without importing Foundation using Xcode 6. About Arbitrary-precision decimal arithmetic in Swift with full math functions and fixed-precision Decimal 32-, 64-, and 128-bit types. What can it do that Double can't? Jul 9, 2023 · The BigDecimal package provides arbitrary-precision (with an adjustable upper limit for performance) and fixed-precision decimal arithmetic in Swift. Feb 11, 2026 · 🌸 Swift Decimal Numbers When you work with decimal numbers like 3. Jan 10, 2021 · Swift Rounding Floats and Doubles in Swift Learn how to round decimal numbers up, down, and with custom decimal precision in Swift. You can specify rounding modes and the number of decimal places using NSDecimalNumberHandler. mle zft dbc fcq dpx hcv wxc aki qbg ohx ktp ijk chu iab ldh