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
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]
其他回答
在斯威夫特
从字符串的两侧修剪空格和换行:
var url: String = "\n http://example.com/xyz.mp4 "
var trimmedUrl: String = url.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet())
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):
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
}
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
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。