String formatting in Swift

Question

I can't seem to understand why the following does not work:

var content : NSString = ""
let myLabel : UILabel = self.view.viewWithTag(i) as UILabel
content += String(format:"var %@ = false;", myLabel.text)

I get the following error:

NSString is not identical to 'UInt8'

Midhun MP · Accepted Answer · 2015-02-10 04:24:10Z

1

It's because NSString class doesn't support appending string using +. It only supports if you use String. You can fix that issue by:

var content : String = ""
let myLabel : UILabel = self.view.viewWithTag(i) as UILabel
content += String(format:"var %@ = false;", myLabel.text!)

answered Feb 10, 2015 at 4:24

Midhun MP

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1 Comment

@JeremyPope: I'm using XCode 6.1.1 In that it's not working now checked in latest beta.

nico · Accepted Answer · 2015-02-10 05:09:17Z

0

try using String interpolation:

content += "var \(myLabel.text) = false;"

answered Feb 10, 2015 at 5:09

nico

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SarahR · Accepted Answer · 2015-02-10 05:15:39Z

0

Instead of using format, why not use Swift's string interpolation?

content += "var \(myLabel.text!) = false;"

It doesn’t give you the numeric formatting that is so useful in NSString's format, but you are just inserting a string with no formatting required.

However the use of ! without checking always makes me twitch, so how about something like:

if let labelText = myLabel.text {
    content += "var \(labelText) = false;"
}

answered Feb 10, 2015 at 5:15

SarahR

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