IOS NSString字符串操作

0.截取匹配到的某段字符：

            NSString *result=@<span style="font-family: Arial, Helvetica, sans-serif;">"partner=\"2088101568353491\"&seller_id=\"2088101568353491\"&out_trade_no=\"YR2VGG3G1I31XDZ\"&subject=\"1\"&body=\"</span><span class="s1" style="font-family: Arial, Helvetica, sans-serif;">我是测试数据</span><span style="font-family: Arial, Helvetica, sans-serif;">\"&total_fee=\"0.02\"&notify_url=\"http://www.xxx.com\"&service=\"mobile.securitypay.pay\"&payment_type=\"1\"&_input_charset=\"utf-8\"&it_b_pay=\"30m\"&show_url=\"m.alipay.com\"&sign=\"GsSZgPloF1vn52XAItRAldwQAbzIgkDyByCxMfTZG%2FMapRoyrNIJo4U1LUGjHp6gdBZ7U8jA1kljLPqkeGv8MZigd3kH25V0UK3Jc3C94Ngxm5S%2Fz5QsNr6wnqNY9sx%2Bw6DqNdEQnnks7PKvvU0zgsynip50lAhJmflmfHvp%2Bgk%3D\"&sign_type=\"RSA\"" </span>
";
            NSRange range = [result rangeOfString:@"out_trade_no=\""];//匹配得到的下标
            NSRange range2 = [result rangeOfString:@"\"&subject"];
            range.location=range.location+range.length;
            range.length=range2.location-range.location;
            
            NSString *out_trade_no= [result substringWithRange:range];//截取范围类的字符串
            out_trade_no = [out_trade_no stringByReplacingOccurrencesOfString:@"\"" withString:@""];
            NSLog(@"截取的值为：%@",out_trade_no);

1.截取字符串

NSString*string =@"sdfsfsfsAdfsdf";
string = [string substringToIndex:7];//截取下标7之后的字符串
NSLog(@"截取的值为：%@",string);
[string substringFromIndex:2];//截取下标2之前的字符串
NSLog(@"截取的值为：%@",string);

2.匹配字符串

NSString*string =@"sdfsfsfsAdfsdf";
NSRange range = [stringrangeOfString:@"f"];//匹配得到的下标
NSLog(@"rang:%@",NSStringFromRange(range));
string = [string substringWithRange:range];//截取范围类的字符串
NSLog(@"截取的值为：%@",string);

3.分隔字符串

NSString*string =@"sdfsfsfsAdfsdf";

NSArray *array = [string componentsSeparatedByString:@"A"]; //从字符A中分隔成2个元素的数组
NSLog(@"array:%@",array); //结果是adfsfsfs和dfsdf