关于空格:从NSString的末尾修剪空格

Trim spaces from end of a NSString

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


使用-stringByTrimmingCharactersInSet:

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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)。

斯威夫特3

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


另一个解决方案是创建可变字符串:

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//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"


干得好...

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- (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)];
}

所以现在就叫它吧。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:

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

resultString最后将没有空格。


要从Swift中的字符串的开头和结尾删除空格:

斯威夫特3

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string.trimmingCharacters(in: .whitespacesAndNewlines)

以前的Swift版本

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string.stringByTrimmingCharactersInSet(.whitespaceAndNewlineCharacterSet()))


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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

还有很多其他的CharacterSets。根据您的要求自行检查。


这将仅删除您选择的尾随字符。

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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
}


Swift版本

只修剪字符串末尾的空格:

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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:

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


要修剪所有尾随空格字符(我猜这实际上是你的意图),以下是一个非常简洁明了的方法:

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

一行,带有一些正则表达式。


在Objective-C中只修剪一端而不是两端的简单解决方案:

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@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

并且仅用于修剪开头的对称实用程序:

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@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

在斯威夫特

要从字符串的两边修剪空格和换行符:

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

这里描述了解决方案:如何从NSString的右端删除空格?

将以下类别添加到NSString:

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- (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]];
}

你这样使用它:

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[yourNSString stringByTrimmingTrailingWhitespaceAndNewlineCharacters]


我想出了这个函数,它基本上与Alex的答案中的行为类似:

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-(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。


let string ="Test Trimmed String"

对于删除空格和新行使用以下代码: -

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

仅用于删除代码中使用字符串的空格: -

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


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