Escape Quotes in Objective-C

Question

I'm using this code snippet to encode characters to be friendly with a POST request:

   NSString *unescaped = [textField text];
   NSString *escapedString = (__bridge_transfer NSString *)CFURLCreateStringByAddingPercentEscapes(
                                                                                  NULL,
                                                                                  (__bridge_retained CFStringRef)unescaped,
                                                                                  NULL,
                                                                                  (CFStringRef)@"!*'();:@&=+$,/?%#[]",
                                                                                  kCFStringEncodingUTF8);

Which works great, but does not add escape Quotation marks: "

How do I escape Quotation marks in IOS?

score 16 · Accepted Answer · edited Nov 05 '21 at 10:06

16

I needed to take the user inputted NSString from [textField text] and make sure that if there are quotation marks in the string, they are escaped properly in order to send through a POST statement.

My solution was:

unescaped = [unescaped stringByReplacingOccurrencesOfString:@"\"" withString:@"\\\""];

edited Nov 05 '21 at 10:06

Nimantha

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answered Apr 12 '12 at 09:27

Moe

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2

why not use NSRegularExpression's "escapedPatternForString:" class method? – Manoj Dec 09 '14 at 19:00

score 4 · Answer 2 · answered Apr 14 '12 at 07:54

First, you don't want to use __bridge_retained in your cast to a CFStringRef. Just use __bridge.

Second, you don't have to escape the quotes manually by string replacement. Just add the quote character to the set of characters to be quoted when calling CFURLCreateStringByAddingPercentEscapes(). Like so:

NSString *unescaped = [textField text];
NSString *escapedString = CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(NULL,
                                                                                    (__bridge CFStringRef)unescaped,
                                                                                    NULL,
                                                                                    CFSTR("!*'();:@&=+$,/?%#[]\""),
                                                                                    kCFStringEncodingUTF8));

(In addition to adding the quote to the set, I changed to use CFBridgingRelease() rather than a __bridge_transfer cast because I find it clearer. It satisfies the feeling that all CF "Create" functions need a corresponding "Release". Also, I changed the use of a @"" literal cast to CFStringRef to just a CFSTR("") literal.)

score 3 · Answer 3 · answered Apr 12 '12 at 03:41

3

Quotes are to be escaped with \".

As in:

(CFStringRef)@"I'm an \"example\""

answered Apr 12 '12 at 03:41

CodaFi

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I know this, I want you to know how to get a user inputted `"` and change it to: `\"` – Moe Apr 12 '12 at 09:19

score 0 · Answer 4 · edited Nov 05 '21 at 10:07

0

Try using \" instead of using " directly...

Special Characters like Quotes, slashes and others require \ to make that character to remove its special functionality.

edited Nov 05 '21 at 10:07

Nimantha

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answered Apr 12 '12 at 03:38

adi27

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Escape Quotes in Objective-C

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