how to replace one substring with another in Objective C?

Question

I want to replace an NSString substring with another substring in Objective C.

I know how to locate the substring I want to replace:

        NSRange range = [string rangeOfString:substringIWantToReplace];
        NSString *substring = [string substringFromIndex:NSMaxRange(range)];

But when it comes to actually removing/replacing it, I'm a little confused. Do I follow the C++ method at Replace substring with another substring C++? Or the C method at how to replace substring in c?? There's a related question at Objective-C: Substring and replace, but the string in question is a URL, so I don't think I can use the answers.

score 7 · Accepted Answer · edited May 23 '17 at 10:26

I think your answer is here Replace occurrences of NSString - iPhone: [response stringByReplacingOccurrencesOfString:@"aaa" withString:@"bbb"]; defenetly works on any string and URL also.

If your concern about percent-notation of url and you want to be sure it will be replaced properly, you can firstly decode string, replace, and then encode:

// decode
NSString *path = [[@"path+with+spaces"
    stringByReplacingOccurrencesOfString:@"+" withString:@" "]
    stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
// replace
path = [path stringByReplacingOccurrencesOfString:@"aaa" withString:@"bbb"]
// encode
path = CFURLCreateStringByAddingPercentEscapes(
                                               NULL,
                                               (CFStringRef)path,
                                               NULL,
                                               (CFStringRef)@"!*'\"();:@&=+$,/?%#[]% ",
                                               kCFStringEncodingUTF8 );

Thank you! I meant actually that the string in the other question was a URL, where my string isn't. The answers in that question seem based on the fact that it's a URL. But anyway your answer gave me what I needed--thank you! — Joel Derfner, Jan 04 '13 at 02:14

score 3 · Answer 2 · answered Jan 04 '13 at 02:03

3

This is how I check for a substring and replace/remove substrings from NSString:

if([titleName rangeOfString:@"&quot;"].location != NSNotFound) {
     titleName = [titleName stringByReplacingOccurrencesOfString:@"&quot;" withString:@"\""];
}

answered Jan 04 '13 at 02:03

user990230

307
5
13

Very helpful but the other answerer got here first so I had to give him credit--still, thanks so much. – Joel Derfner Jan 04 '13 at 02:13
No Problem, just wanted to show how easy it is to do this task with Objective-C's inbuilt methods. – user990230 Jan 04 '13 at 02:17

how to replace one substring with another in Objective C?

2 Answers2

Linked