字符串反转

写个NSString 分类

@interface NSString (extension)
-(NSString *)getReverseString;
@end

@implementation NSString (extension)
-(NSString *)getReverseString
{
    NSMutableString * newStrM = [NSMutableString string];
    for (int i = 0; i<self.length; i++) {
        NSString * lastStr = [self substringWithRange:NSMakeRange(self.length - i - 1, 1)];
        
        [newStrM appendString:lastStr];
    }
    return newStrM;
}
@end

在VC中使用

- (void)viewDidLoad {
    [super viewDidLoad];
    NSString * myStr = @"颠倒是非违反了可我姐夫渴望";
    NSString * reverseMyStr = [myStr getReverseString];
    NSLog(@"reverseMyStr:%@",reverseMyStr);
}

2019-07-15 14:14:04.978671+0800 信号量[31560:2357516] reverseMyStr:望渴夫姐我可了反违非是倒颠