MetricPrefixNumberFormatter is an NSNumberFormatter subclass designed to format large and small numbers using the metric prefixes. This is a must have library, if your app displays potentially big numbers like a number of views, likes, etc, or deals with calculations that may potentially involve very small numbers.

1200 -> 1.2 k
12300000 -> 12.3 M
0.0017 -> 1.7 m

Main features

• Supports all metric prefixes: from yotta (10^24) to yocto (10^-24).
• Localizable using the localizationDictionary property.
• Configurable units and delimiters.

Examples

// 1122300 -> 1.12 M
let nf = MetricPrefixNumberFormatter()
nf.minimumFractionDigits = 2
nf.stringWithMetricPrefix(from: 1122300)

// 0.001 -> 1 mA
let nf = MetricPrefixNumberFormatter()
nf.unit = "A"
nf.stringWithMetricPrefix(from: 0.001)

// 1200 -> 1.2KV
let nf = MetricPrefixNumberFormatter()
nf.unit = "V"
nf.delimiter = ""
nf.stringWithMetricPrefix(from: 1200)

Since MetricPrefixNumberFormatter is a subclass of NSNumberFormatter its output can be configured the same way as with NSNumberFormatter. A good overview of NSNumberFormatter output setup using the minimum/maximumSignificantDigits, minimum/maximumFractionDigits, and usesSignificantDigits properties is presented in this guide by @samwize.

You can also check out provided example iOS app that shows you how various numbers are formatted by MetricPrefixNumberFormatter.

$ pod try MetricPrefixNumberFormatter

Requirements

• iOS 8+
• Xcode 10 / Swift 4.2 and higher

Installation using CocoaPods

pod 'MetricPrefixNumberFormatter', '~> 1.0.0'

License

MetricPrefixNumberFormatter is available under the MIT license. See LICENSE file for more information.