从这里的答案来看: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
}

要修剪所有尾随的空格字符(我猜这实际上是你的意图)，下面是一种相当干净简洁的方法。

斯威夫特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)];

一行，加上一段正则表达式。

let string = "测试修剪过的字符串"

对于删除空白和新行使用以下代码:-

let str_trim = yourString。trimmingCharacters (.whitespacesAndNewlines):

对于仅从字符串中删除空格使用以下代码:-

let str_trim = yourString。trimmingCharacters (.whitespaces):

我想出了这个函数，它的行为基本类似于Alex的答案:

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

whitespaceCharacterSet除了空格本身还包括制表符，在我的情况下不能出现。所以我想一个简单的比较就足够了。

在Swift中删除字符串开头和结尾的空格:

斯威夫特3

string.trimmingCharacters(in: .whitespacesAndNewlines)

Swift以前的版本

string.stringByTrimmingCharactersInSet(.whitespaceAndNewlineCharacterSet()))

解决方案在这里描述:如何从NSString的右端删除空白?

添加以下类别到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]];
}

你可以这样使用它:

[yourNSString stringByTrimmingTrailingWhitespaceAndNewlineCharacters]