字符串的倒序输出

-(NSString *)getReverseString:(NSString *)tempString
{
NSLog(@"%@",tempString);

NSMutableString *mutableString =[NSMutableString stringWithString:tempString];

for(int i = 0;i<tempString.length;i++)
{
    
    NSString *subStr1 = [tempString substringWithRange:NSMakeRange(i, 1)];
    NSString *subStr2 = [tempString substringWithRange:NSMakeRange(tempString.length - i-1, 1)];
    
    NSRange range1 = [tempString rangeOfString:subStr1];
    NSRange range2 = [tempString rangeOfString:subStr2];
    
    
    [mutableString replaceCharactersInRange:range1 withString:subStr2];
    [mutableString replaceCharactersInRange:range2 withString:subStr1];
    
}
tempString = [NSString stringWithFormat:@"%@",mutableString];
return tempString;

}