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 = @"\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 ;
 }

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：

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