iOS trimEnd

- (NSString *)trimEndWithString:(NSString *)string end:(NSString *)end
{
    NSUInteger length = [string length];
    if (length < 2) return @"";
    
    //截取最后一位
    NSString *last = [string substringFromIndex:length - 1];
    
    //trimEnd('end')
    if ([last isEqualToString:end]) {
        
        string = [string substringWithRange:NSMakeRange(0, length - 1)];
    }
    
    return string;
}