CODEWITHSUNDEEP
iosswiftdecimalformat
juelizabeth
juelizabeth

Reputation: 505

decimal place value not working in swift

I'm not really sure what I am doing wrong here. I have a double:

let distanceInMiles = distanceInMeters/1609.344 and the results are 2.99685063032388e-09

But I want to round the number to one decimal place, so I do this:

let miles = String(format: "%.1f", distanceInMiles)

But when I print it out miles = 0.0. The decimal place works but it turns my number into 0 instead of 2.9

Upvotes: 0

Views: 323

Answers (1)

bjtitus
bjtitus

Reputation: 4270

2.99685063032388e-09 is not equal to 2.9, it is 0.00000000299685063032388

http://www.wolframalpha.com/input/?i=2.99685063032388e-09

There is actually a cool way to do this, using the exponent format specifier instead of float. (From this list https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/Strings/Articles/formatSpecifiers.html)

let miles = String(format: "%.1e", distanceInMiles)

Upvotes: 2

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