我需要从字符串的末尾删除空格。我该怎么做呢? 示例:如果字符串是“Hello”,它必须变成“Hello”
当前回答
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。
其他回答
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
}
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"
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]
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。
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。