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

Swift version

Only trims spaces at the end of the String:

private func removingSpacesAtTheEndOfAString(var str: String) -> String {
    var i: Int = countElements(str) - 1, j: Int = i

    while(i >= 0 && str[advance(str.startIndex, i)] == " ") {
        --i
    }

    return str.substringWithRange(Range<String.Index>(start: str.startIndex, end: advance(str.endIndex, -(j - i))))
}

Trims spaces on both sides of the String:

var str: String = " Yolo "
var trimmedStr: String = str.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet())

Answer 2

To trim all trailing whitespace characters (I'm guessing that is actually your intent), the following is a pretty clean & concise way to do it.

Swift 5:

let trimmedString = string.replacingOccurrences(of: "\\s+$", with: "", options: .regularExpression)

Objective-C:

NSString *trimmedString = [string stringByReplacingOccurrencesOfString:@"\\s+$" withString:@"" options:NSRegularExpressionSearch range:NSMakeRange(0, string.length)];

One line, with a dash of regex.

Answer 3

let string = " Test Trimmed String "

For Removing white Space and New line use below code :-

let str_trimmed = yourString.trimmingCharacters(in: .whitespacesAndNewlines)

For Removing only Spaces from string use below code :-

let str_trimmed = yourString.trimmingCharacters(in: .whitespaces)

Answer 4

Taken from this answer here: https://stackoverflow.com/a/5691567/251012

- (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
}

Answer 5

Another solution involves creating mutable string:

//make mutable string
NSMutableString *stringToTrim = [@" i needz trim " mutableCopy];

//pass it by reference to CFStringTrimSpace
CFStringTrimWhiteSpace((__bridge CFMutableStringRef) stringToTrim);

//stringToTrim is now "i needz trim"

Answer 6

I came up with this function, which basically behaves similarly to one in the answer by Alex:

-(NSString*)trimLastSpace:(NSString*)str{
    int i = str.length - 1;
    for (; i >= 0 && [str characterAtIndex:i] == ' '; i--);
    return [str substringToIndex:i + 1];
}

whitespaceCharacterSet besides space itself includes also tab character, which in my case could not appear. So i guess a plain comparison could suffice.