我在寻找一个快速简便的方法，从剥离非字母数字字符NSString 。 可能是一些使用NSCharacterSet ，但我累了，似乎没有任何返回只包含字符串中的字母数字字符的字符串。
Answer 1:
我们可以通过拆分，然后加入做到这一点。 需要OS X 10.5+的componentsSeparatedByCharactersInSet：
NSCharacterSet *charactersToRemove = [[NSCharacterSet alphanumericCharacterSet] invertedSet];
NSString *strippedReplacement = [[someString componentsSeparatedByCharactersInSet:charactersToRemove] componentsJoinedByString:@""];
Answer 2:
在斯威夫特的componentsJoinedByString被替换join(...)所以在这里它只是取代非字母数字字符的空间。
let charactersToRemove = NSCharacterSet.alphanumericCharacterSet().invertedSet
let strippedReplacement = " ".join(someString.componentsSeparatedByCharactersInSet(charactersToRemove))
对于Swift2 ...
var enteredByUser = field.text .. or whatever
let unsafeChars = NSCharacterSet.alphanumericCharacterSet().invertedSet
enteredByUser = enteredByUser
.componentsSeparatedByCharactersInSet(unsafeChars)
.joinWithSeparator("")
如果要删除只是一个字符，例如删除所有的回报...
enteredByUser = enteredByUser
.componentsSeparatedByString("\n")
.joinWithSeparator("")
Answer 3:
我清盘做是创造一个NSCharacterSet和-invertedSet方法，我发现（这是一个奇迹什么的睡眠一个小时做的文档阅读能力）。 下面的代码片段，假设someString是要删除非字母数字字符的字符串：
NSCharacterSet *charactersToRemove =
[[ NSCharacterSet alphanumericCharacterSet ] invertedSet ];
NSString *trimmedReplacement =
[ someString stringByTrimmingCharactersInSet:charactersToRemove ];
trimmedReplacement则包含someString的字母数字字符。
Answer 4:
雨燕3.0版本接受的答案的：
let unsafeChars = CharacterSet.alphanumerics.inverted
let myStrippedString = myString.components(separatedBy: unsafeChars).joined(separator: "")
Answer 5:
清理范畴
我有一个方法调用stringByStrippingCharactersInSet:和stringByCollapsingWhitespace可能是方便刚落项。
@implementation NSString (Cleanup)
- (NSString *)clp_stringByStrippingCharactersInSet:(NSCharacterSet *)set
{
return [[self componentsSeparatedByCharactersInSet:set] componentsJoinedByString:@""];
}
- (NSString *)clp_stringByCollapsingWhitespace
{
NSArray *components = [self componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
components = [components filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:@"self <> ''"]];
return [components componentsJoinedByString:@" "];
}
@end
Answer 6:
这里的斯威夫特版本卡梅伦的类别作为扩展：
extension String {
func stringByStrippingCharactersInSet(set:NSCharacterSet) -> String
{
return (self.componentsSeparatedByCharactersInSet(set) as NSArray).componentsJoinedByString("")
}
func stringByCollapsingWhitespace() -> String
{
var components:NSArray = self.componentsSeparatedByCharactersInSet(NSCharacterSet.whitespaceCharacterSet())
let predicate = NSPredicate(format: "self <> ''", argumentArray: nil)
components = components.filteredArrayUsingPredicate(predicate)
return components.componentsJoinedByString(" ")
}
}
Answer 7:
平原周期将是更快的执行时间，我认为：
@implementation NSString(MyUtil)
- (NSString*) stripNonNumbers {
NSMutableString* res = [NSMutableString new];
//NSCharacterSet *numericSet = [NSCharacterSet decimalDigitCharacterSet];
for ( int i=0; i < self.length; ++i ) {
unichar c = [self characterAtIndex:i];
if ( c >= '0' && c <= '9' ) // this looks cleaner, but a bit slower: [numericSet characterIsMember:c])
[res appendFormat:@"%c", c];
}
return res;
}
@end
Answer 8:
这比提供的答案更有效的方式
+ (NSString *)alphanumericString:(NSString *)s {
NSCharacterSet * charactersToRemove = [[NSCharacterSet alphanumericCharacterSet] invertedSet];
NSMutableString * ms = [NSMutableString stringWithCapacity:[s length]];
for (NSInteger i = 0; i < s.length; ++i) {
unichar c = [s characterAtIndex:i];
if (![charactersToRemove characterIsMember:c]) {
[ms appendFormat:@"%c", c];
}
}
return ms;
}
或作为类别
@implementation NSString (Alphanumeric)
- (NSString *)alphanumericString {
NSCharacterSet * charactersToRemove = [[NSCharacterSet alphanumericCharacterSet] invertedSet];
NSMutableString * ms = [NSMutableString stringWithCapacity:[self length]];
for (NSInteger i = 0; i < self.length; ++i) {
unichar c = [self characterAtIndex:i];
if (![charactersToRemove characterIsMember:c]) {
[ms appendFormat:@"%c", c];
}
}
return ms;
}
@end
文章来源: Strip Non-Alphanumeric Characters from an NSString
