Question

我需要从字符串末尾删除空格。我怎样才能做到这一点？示例：如果字符串为"Hello "，则必须为"Hello"

Answer 1

NSString *string = @" this text has spaces before and after ";
NSString *trimmedString = [string stringByTrimmingCharactersInSet:
                                  [NSCharacterSet whitespaceAndNewlineCharacterSet]];

（这将修剪两端的空白字符）。

Swift 3

let string = " this text has spaces before and after "
let trimmedString = string.trimmingCharacters(in: .whitespacesAndNewlines)

Answer 2

另一种解决方案涉及创建可变字符串：

//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 3

你去......

- (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)];
}

所以现在就叫它。假设你有一个字符串，前面有空格，末尾有空格，你只想删除末尾的空格，你可以像这样调用它：

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

resultString最后将没有空格。

Answer 4

在Swift中仅从字符串的开头和结尾删除空格：

Swift 3

string.trimmingCharacters(in: .whitespacesAndNewlines)

以前的Swift版本

string.stringByTrimmingCharactersInSet(.whitespaceAndNewlineCharacterSet()))

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

还有很多其他角色集。根据您的要求自行检查。

Answer 6

Swift 版本

仅修剪字符串末尾的空格：

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))))
}

修剪字符串两边的空格：

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

Answer 7

这将只删除您选择的尾随字符。

func trimRight(theString: String, charSet: NSCharacterSet) -> String {

    var newString = theString

    while String(newString.characters.last).rangeOfCharacterFromSet(charSet) != nil {
        newString = String(newString.characters.dropLast())
    }

    return newString
}

Answer 8

在Swift中

修剪空间＆amp;字符串两边的换行符：

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

Answer 9

在Objective-C中仅修剪一端而不是两端的简单解决方案：

@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

仅用于修剪开头的对称效用：

@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 10

要修剪所有跟踪空格字符（我想这实际上是您的意图），以下是一种非常简洁的方法：

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

一行，带有一些正则表达式。

Answer 11

此处描述了解决方案：How to remove whitespace from right end of NSString?

将以下类别添加到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]

Answer 12

我想出了这个函数，它基本上与Alex的答案中的行为相似：

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

whitespaceCharacterSet除了空间本身还包括制表符，在我的情况下无法显示。所以我想一个简单的比较就足够了。

Answer 13

let string =“测试修剪后的字符串”

要删除空白和换行符，请使用以下代码：-

let str_trimmed = yourString.trimmingCharacters（在：.whitespacesAndNewlines中）

仅用于从字符串中删除空格，请使用以下代码：-

let str_trimmed = yourString.trimmingCharacters（位于.whitespaces中）

Answer 14

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

从NSString的末尾修剪空格

14 个答案:

Swift 3

以前的Swift版本