stringByTrimmingCharactersInSet: is not removing characters in the middle of the string

Question

I want to remove "#" from my string.

I have tried

 NSString *abc = [@"A#BCD#D" stringByTrimmingCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"#"]];

But it still shows the string as "A#BCD#D"

What could be wrong?

Solution 1

You could try

NSString *modifiedString = [yourString stringByReplacingOccurrencesOfString:@"#" withString:@""];

Solution 2

stringByTrimmingCharactersInSet removes characters from the beginning and end of your string, not from any place in it

For your purpose use stringByReplacingOccurrencesOfString:withString: method as others pointed.

Solution 3

I wrote a category of NSString for that:

- (NSString *)stringByReplaceCharacterSet:(NSCharacterSet *)characterset withString:(NSString *)string {
    NSString *result = self;
    NSRange range = [result rangeOfCharacterFromSet:characterset];

    while (range.location != NSNotFound) {
        result = [result stringByReplacingCharactersInRange:range withString:string];
        range = [result rangeOfCharacterFromSet:characterset];
    }
    return result;
}

You can use it like this:

NSCharacterSet *funnyCharset = [NSCharacterSet characterSetWithCharactersInString:@"#"];
NSString *newString = [string stringByReplaceCharacterSet:funnyCharset withString:@""];

Solution 4

I previously had a relatively complicated recursive answer for this (see edit history of this answer if you'd like to see that answer), but then I found a pretty simple one liner: 

- (NSString *)stringByRemovingCharactersInSet:(NSCharacterSet *)characterSet {
    return [[self componentsSeparatedByCharactersInSet:characterSet] componentsJoinedByString:@""];
}

Solution 5

Refer to the Apple Documentation about: stringByReplacingOccurrencesOfString: method in NSString

NSString *str1=[str stringByReplacingOccurrencesOfString:@"#" withString:@""];

Hope this helps.

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Comments

[ArtOfWarfare]

+1, although I dislike the redundancy caused by using a while loop, so I wrote a method which uses recursion instead (do-while probably could have also removed the redundancies): stackoverflow.com/a/26152034/901641

[manecosta]

took me quite a while to figure why xcode wasn't accepting it :) thanks for the answer by the way.

[CommaToast]

Then why the heck isn't it called "stringByTrimmingCharactersInSetJustFromTheVeryEndOrVeryBegi‌​nning"...

[Vladimir]

I guess trim implies that, but I am not a native english speaker :)