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）

main.m

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

NSString+Trim.h

#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

NSString+Trim.m

#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

结果：

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] “
Kenmu 我是啊武
”去掉前后回车符后为“Kenmu 我是啊武”
2015-05-18 21:07:08.193 OCNSStringTrim[519:18080] “
 Kenmu 我是啊武 
”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”