How to format UInt64.max to add commas

Question

I'm trying to format the integer returned for UInt64.max to add commas to the number. In case it matters, I'm currently writing this out in a "Playground" and I'm using XCode 6.3.2.

Here's the relevant code:

//: Playground - noun: a place where people can play

import UIKit

// MARK: - Integer Bounds

var formatter = NSNumberFormatter()
formatter.numberStyle = .DecimalStyle

println( formatter.stringFromNumber(100000) )
println( formatter.stringFromNumber(100000000) )
println( formatter.stringFromNumber( NSNumber(char: Int8.min) ) )

println( Int8.min )
println( Int8.max )

println( UInt8.min )
println( UInt8.max )

println( Int16.min )
println( formatter.stringFromNumber( NSNumber(short: Int16.min) ) )
println( Int16.max )
println( formatter.stringFromNumber( NSNumber(short: Int16.max) ) )

println( UInt16.min )
println( UInt16.max )
println( formatter.stringFromNumber( NSNumber(unsignedShort: UInt16.max) ) )

println( Int32.min )
println( formatter.stringFromNumber( NSNumber(int: Int32.min) ) )
println( Int32.max )
println( formatter.stringFromNumber( NSNumber(int: Int32.max) ) )

println( UInt32.min )
println( UInt32.max )
println( formatter.stringFromNumber( NSNumber(unsignedInt: UInt32.max) ) )

println( Int64.min )
println( formatter.stringFromNumber( NSNumber(longLong: Int64.min) ) )
println( Int64.max )
println( formatter.stringFromNumber( NSNumber(longLong: Int64.max) ) )

println( UInt64.min ) // 0
println( UInt64.max ) // 18446744073709551615
println( formatter.stringFromNumber( NSNumber(unsignedLongLong: UInt64.max) ) ) // Optional("-1")

All of these return a properly formatted number except the last one (UInt64.max).

As shown, the last line (where I try to use formatter to add the commas) returns Optional("-1").

How could I print UInt64.max formatted with commas?

Looks like a bug to me. It seems that every number > Int64.max is formatted as a negative number. — Martin R, Jun 10 '15 at 22:33
My question here may be a duplicate of this one: http://stackoverflow.com/questions/24218918/why-is-uint64-max-equal-1-in-swift — Ezra Free, Jun 11 '15 at 03:55

mondousage · Answer 1 · 2015-06-10T23:12:19.813

0

In Obj-C (just in case):

NSNumber *num = [NSNumber numberWithDouble:18446744073709551615.];

NSNumberFormatter *formatter;
formatter = [[NSNumberFormatter alloc] init];

formatter.numberStyle = kCFNumberFormatterDecimalStyle;
[formatter setMaximumFractionDigits:0];
[formatter stringFromNumber:num];

NSString *formattedString = [formatter stringFromNumber:num];

NSLog(@"%@", formattedString);

Results 18,446,744,073,709,600,000

In Swift

    var num = 18446744073709551615.0

    var formatter = NSNumberFormatter()
    formatter.numberStyle = .DecimalStyle
    formatter.maximumFractionDigits = 0
    formatter.stringFromNumber(num)

    println(formatter.stringFromNumber(num))

Results Optional("18,446,744,073,709,600,000")

edited Jun 10 '15 at 23:12

answered Jun 10 '15 at 23:05

mondousage

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`18,446,744,073,709,600,000` is not really the expected output :) A `Double` cannot represent `UInt64.max` precisely. – Martin R Jun 10 '15 at 23:16
1

Sorry, but I am hoping to print the value of `UInt64.max` formatted with commas, not to set the number `18446744073709551615` into a variable and print that variable formatted with commas. – Ezra Free Jun 11 '15 at 13:47
Converting to double changed the value regardless. Int overflow issues. Whoops! – mondousage Jun 11 '15 at 16:41

How to format UInt64.max to add commas

1 Answers1