从NSString结尾开始修剪空格

我需要从字符串的结尾删除空格。我该怎么做呢? 例如:如果字符串是"Hello "，它必须变成"Hello"

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最佳答案

从这里的答案: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
}
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另一个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"
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给你…

- (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)];
}

现在就叫它。假设你有一个字符串，它前面有空格，后面也有空格，你只想去掉末尾的空格，你可以这样调用它:

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

resultString的结尾将没有空格。

小开

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。

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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

还有许多其他字符集。根据你的要求自己检查一下。

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NSString* NSStringWithoutSpace(NSString* string)
{
return [string stringByReplacingOccurrencesOfString:@" " withString:@""];
}
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斯威夫特版本

只修整字符串末尾的空格:

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))))
}

修整字符串两侧的空格:

var str: String = " Yolo "
var trimmedStr: String = str.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet())
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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()))
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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
}
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在斯威夫特

修剪空间;字符串两侧的换行符:

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

和一个对称的实用工具，仅用于修剪开头:

@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
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解决方案描述在这里: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]
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为了修剪所有落后于空白字符(我猜这是实际上你的意图)，下面是一个非常干净的&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。

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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):


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