WEBVTT 00:00.620 --> 00:01.040 Okay. 00:01.040 --> 00:04.940 So next up let's do some more advanced things with the strings. 00:04.940 --> 00:09.650 So in this example here we've got a Unicode text. 00:09.860 --> 00:13.130 So to be honest I just copied this over the internet. 00:13.130 --> 00:16.010 I just don't even know what language that is. 00:16.040 --> 00:20.060 That's not the characters the Latin characters I know. 00:20.060 --> 00:28.400 And for such cases you can't just use strlen because this would completely break it down. 00:29.960 --> 00:36.620 So if I try something like that, this file is called String Advanced. 00:36.650 --> 00:37.910 Let me run that. 00:40.490 --> 00:43.040 Don't even get a result, to be honest. 00:43.250 --> 00:44.210 Maybe. 00:45.440 --> 00:46.940 Okay, so let's run that. 00:46.940 --> 00:50.810 And this says that the length is 15. 00:50.810 --> 00:58.610 Well I'm no expert in this alphabet, but it doesn't really look like 15 characters. 00:58.610 --> 01:09.660 So for such cases we need to use the multibyte versions of string functions and they have this M prefix. 01:09.690 --> 01:17.880 Now watch out when you are working with Unicode, because if you would use any other function that modifies 01:17.880 --> 01:23.160 or does anything to such a string once, it really might corrupt such string. 01:23.160 --> 01:33.210 So if you are dealing with the UTF text multi-byte strings, you need to use those M functions. 01:33.240 --> 01:35.220 Now let's see if this is any better. 01:35.250 --> 01:38.010 Well it looks like five characters. 01:38.010 --> 01:40.980 So now we've got the correct value. 01:41.430 --> 01:49.500 Now another example and something you actually might be often doing is the Urlencode function. 01:50.580 --> 01:54.150 Now let's have an example with URL encoding. 01:54.870 --> 02:02.280 So URL encoding is essentially making sure that you can pass a string safely in a URL. 02:02.370 --> 02:09.030 Now in this example here well URLs contain some special characters that have special meaning like the 02:09.060 --> 02:15.960 question mark, to pass the parameters and the end sign to separate different parameters. 02:15.960 --> 02:24.060 So to be able to pass strings that contains those special characters in a URL, you need to encode them. 02:24.510 --> 02:33.270 So you will run the URL encode function which opposite of its URL decode, which basically lets you 02:33.270 --> 02:35.670 get back the original string. 02:38.100 --> 02:41.040 So let's see how this would look like. 02:42.930 --> 02:43.830 Let me run that. 02:43.830 --> 02:47.580 And this is how this URL would look like. 02:47.580 --> 02:49.770 Now why this is useful. 02:49.860 --> 02:56.280 Well I can pass this text as a parameter to some other URL. 02:56.280 --> 03:02.760 And it would be at this URL encoded can be safely passed. 03:02.760 --> 03:05.610 And then I can decode that. 03:05.610 --> 03:15.520 So when I receive such string and I know it is a URL that I need to use for anything, Then I do urldecode 03:15.520 --> 03:16.960 on the other side. 03:19.420 --> 03:25.840 So let me just copy the encoded version and decode it back. 03:27.970 --> 03:34.750 So if I run that, then I get this original URL which I can do whatever I need to with. 03:34.780 --> 03:40.420 Now this is not only for encoding the whole URLs like you see here. 03:40.450 --> 03:47.920 You might just encode a string that you suspect of having some special characters. 03:48.610 --> 03:51.610 For example, a company name. 03:51.610 --> 03:58.210 If this is Johnson and Johnson. 04:00.610 --> 04:04.990 You can't pass safely such a string as a URL parameter. 04:04.990 --> 04:11.710 It needs to be encoded to cover the spaces and the end sign, etc.. 04:13.180 --> 04:17.750 Okay, next up, let's imagine that we have user input like this. 04:17.750 --> 04:21.680 So we might want to present code on the screen. 04:22.040 --> 04:24.260 For example I'm doing this on my website. 04:24.260 --> 04:26.060 So this is useful for me. 04:26.060 --> 04:29.060 But also you need to be wary of user input. 04:29.060 --> 04:37.520 So someone might want to use HTML tags or add some code to input, even if maybe you are asking for 04:37.520 --> 04:38.330 something else. 04:38.330 --> 04:47.120 Maybe you want a blog post title and malicious actors, let's call them this way, might try to, you 04:47.120 --> 04:50.000 know, enter what should not be entered. 04:50.000 --> 04:57.560 And in this case, we would like to basically escape some special characters and escape the HTML tags 04:57.560 --> 05:01.310 so they are not interpreted by the browser as tags. 05:01.340 --> 05:06.560 Instead, they are converted to the so-called HTML entities. 05:07.070 --> 05:14.570 Now with this text, what we would like to do is to use the HTML entities function. 05:14.570 --> 05:16.550 So I know those functions. 05:16.550 --> 05:20.390 Really those functions naming doesn't really make sense. 05:20.390 --> 05:21.450 There are. 05:21.480 --> 05:23.850 Those names are all over the place. 05:23.880 --> 05:27.210 Anyway, let's see how this would look like. 05:27.210 --> 05:33.840 So this is string advanced and this is it. 05:33.840 --> 05:37.170 So as you see it's HTML entities everywhere. 05:37.170 --> 05:45.330 And this is what can be then safely stored and displayed and won't be interpreted as HTML. 05:46.800 --> 05:55.200 Finally let's cover the base64 encode and basically this base64 algorithm. 05:55.200 --> 06:03.570 So this encoding can represent binary data using just a set of 64 characters that are letters numbers. 06:03.600 --> 06:09.900 And it's very useful if you'd like to include some data in your URL parameters. 06:09.900 --> 06:12.030 And this data might be anything. 06:12.030 --> 06:13.950 It can be an image even. 06:14.190 --> 06:19.140 And it's also useful to store some kind of binary data. 06:19.170 --> 06:27.540 So maybe some images or other types of files in databases that don't support binary storage. 06:27.570 --> 06:28.470 Also. 06:28.500 --> 06:32.070 Encoding is used for email attachments. 06:32.070 --> 06:37.230 So let's do something easy with this. 06:37.230 --> 06:42.780 A simple example with just some text looks like this. 06:42.780 --> 06:48.840 And maybe I can just var dump this right away like this. 06:49.650 --> 06:52.800 And let's see how this would look like. 06:54.150 --> 06:57.390 So this is our encoded text. 06:59.490 --> 07:06.030 Now if I instead assign that to a variable I should be able to decode that back. 07:07.080 --> 07:08.370 So now let me. 07:08.400 --> 07:13.080 VAR dump base 64 07:14.820 --> 07:18.720 decode with the encoded text to confirm. 07:21.240 --> 07:22.260 And there it is. 07:22.260 --> 07:28.770 So this is our decoded text that we previously encoded with this base64 encoding.