Objective-C语法之字符串NSString去掉前后空格或回车符（可以是NSCharacterSet类型的其它字符）

#import <Foundation/Foundation.h>
#import "NSString+Trim.h"
int main(int argc, const char * argv[]) {
@autoreleasepool {
NSString *strSource = @" Kenmu 我是啊武 ";
NSLog(@"“%@”去掉前后空格后为“%@”", strSource, [NSString trimWhitespace:strSource]);

strSource = @"\nKenmu 我是啊武\n";
NSLog(@"“%@”去掉前后回车符后为“%@”", strSource, [NSString trimNewline:strSource]);

strSource = @"\n Kenmu 我是啊武 \n";
NSLog(@"“%@”去掉前后空格和回车符后为“%@”", strSource, [NSString trimWhitespaceAndNewline:strSource]);

strSource = @"$+Kenmu 我是啊武+$";
NSLog(@"“%@”去掉前后$和+符后为“%@”", strSource, [NSString trim:strSource trimCharacterSet:[NSCharacterSet symbolCharacterSet]]);
}
return 0;
}

#import <Foundation/Foundation.h>
@interface NSString (Trim)
+ (NSString *)trim:(NSString *)val trimCharacterSet:(NSCharacterSet *)characterSet;
+ (NSString *)trimWhitespace:(NSString *)val;
+ (NSString *)trimNewline:(NSString *)val;
+ (NSString *)trimWhitespaceAndNewline:(NSString *)val;
@end

#import "NSString+Trim.h"
@implementation NSString (Trim)
+ (NSString *)trim:(NSString *)val trimCharacterSet:(NSCharacterSet *)characterSet {
NSString *returnVal = @"";
if (val) {
returnVal = [val stringByTrimmingCharactersInSet:characterSet];
}
return returnVal;
}
+ (NSString *)trimWhitespace:(NSString *)val {
return [self trim:val trimCharacterSet:[NSCharacterSet whitespaceCharacterSet]]; //去掉前后空格
}
+ (NSString *)trimNewline:(NSString *)val {
return [self trim:val trimCharacterSet:[NSCharacterSet newlineCharacterSet]]; //去掉前后回车符
}
+ (NSString *)trimWhitespaceAndNewline:(NSString *)val {
return [self trim:val trimCharacterSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; //去掉前后空格和回车符
}
@end

2015-05-18 21:07:08.192 OCNSStringTrim[519:18080] “ Kenmu 我是啊武 ”去掉前后空格后为“Kenmu 我是啊武”
2015-05-18 21:07:08.193 OCNSStringTrim[519:18080] “\nKenmu 我是啊武\n”去掉前后回车符后为“Kenmu 我是啊武”
2015-05-18 21:07:08.193 OCNSStringTrim[519:18080] “\n Kenmu 我是啊武 \n”去掉前后空格和回车符后为“Kenmu 我是啊武”
2015-05-18 21:07:08.194 OCNSStringTrim[519:18080] “$+Kenmu 我是啊武+$”去掉前后$和+符后为“Kenmu 我是啊武”