Trim spaces from end of a NSString

Question

I need to remove spaces from the end of a string. How can I do that? Example: if string is \"Hello \" it must become \"Hello\"

Answer 1

The solution is described here: How to remove whitespace from right end of NSString?

Add the following categories to NSString:

- (NSString *)stringByTrimmingTrailingCharactersInSet:(NSCharacterSet *)characterSet {
    NSRange rangeOfLastWantedCharacter = [self rangeOfCharacterFromSet:[characterSet invertedSet]
                                                               options:NSBackwardsSearch];
    if (rangeOfLastWantedCharacter.location == NSNotFound) {
        return @"";
    }
    return [self substringToIndex:rangeOfLastWantedCharacter.location+1]; // non-inclusive
}

- (NSString *)stringByTrimmingTrailingWhitespaceAndNewlineCharacters {
    return [self stringByTrimmingTrailingCharactersInSet:
            [NSCharacterSet whitespaceAndNewlineCharacterSet]];
}

And you use it as such:

[yourNSString stringByTrimmingTrailingWhitespaceAndNewlineCharacters]

Answer 2

NSString* NSStringWithoutSpace(NSString* string)
{
    return [string stringByReplacingOccurrencesOfString:@" " withString:@""];
}

Answer 3

A simple solution to only trim one end instead of both ends in Objective-C:

@implementation NSString (category)

/// trims the characters at the end
- (NSString *)stringByTrimmingSuffixCharactersInSet:(NSCharacterSet *)characterSet {
    NSUInteger i = self.length;
    while (i > 0 && [characterSet characterIsMember:[self characterAtIndex:i - 1]]) {
        i--;
    }
    return [self substringToIndex:i];
}

@end

And a symmetrical utility for trimming the beginning only:

@implementation NSString (category)

/// trims the characters at the beginning
- (NSString *)stringByTrimmingPrefixCharactersInSet:(NSCharacterSet *)characterSet {
    NSUInteger i = 0;
    while (i < self.length && [characterSet characterIsMember:[self characterAtIndex:i]]) {
        i++;
    }
    return [self substringFromIndex:i];
}

@end

Answer 4

Here you go...

- (NSString *)removeEndSpaceFrom:(NSString *)strtoremove{
    NSUInteger location = 0;
    unichar charBuffer[[strtoremove length]];
    [strtoremove getCharacters:charBuffer];
    int i = 0;
    for(i = [strtoremove length]; i >0; i--) {
        NSCharacterSet* charSet = [NSCharacterSet whitespaceCharacterSet];
        if(![charSet characterIsMember:charBuffer[i - 1]]) {
            break;
        }
    }
    return [strtoremove substringWithRange:NSMakeRange(location, i  - location)];
}

So now just call it. Supposing you have a string that has spaces on the front and spaces on the end and you just want to remove the spaces on the end, you can call it like this:

NSString *oneTwoThree = @"  TestString   ";
NSString *resultString;
resultString = [self removeEndSpaceFrom:oneTwoThree];

resultString will then have no spaces at the end.

Answer 5

NSString *trimmedString = [string stringByTrimmingCharactersInSet:
                              [NSCharacterSet whitespaceAndNewlineCharacterSet]];
//for remove whitespace and new line character

NSString *trimmedString = [string stringByTrimmingCharactersInSet:
                              [NSCharacterSet punctuationCharacterSet]]; 
//for remove characters in punctuation category

There are many other CharacterSets. Check it yourself as per your requirement.

Answer 6

In Swift

To trim space & newline from both side of the String:

var url: String = "\n   http://example.com/xyz.mp4   "
var trimmedUrl: String = url.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet())