1 00:00:01,660 --> 00:00:08,350 String comparison in beshe can be from the beginning found as difficult because it has many rules such 2 00:00:08,350 --> 00:00:12,530 as when to score marks and to double brackets. 3 00:00:12,580 --> 00:00:16,190 In addition some scripts using double square brackets are not. 4 00:00:16,360 --> 00:00:23,310 So generally when you don't know what is going on here you may feel kind of lost but I need to tell 5 00:00:23,310 --> 00:00:28,200 you that string comparison is quite easy when you know the rules. 6 00:00:28,210 --> 00:00:34,000 In fact I believe that by end of this lecture you say OK it's quite simple. 7 00:00:34,060 --> 00:00:37,590 So let's look how to compare two strings. 8 00:00:39,420 --> 00:00:44,850 For string comparison we are using single square brackets and inside it. 9 00:00:44,880 --> 00:00:50,370 Dollar sign for is the variable equal sign or sign second variable. 10 00:00:50,370 --> 00:00:56,160 Those two variables are inside double quotation marks. 11 00:00:56,160 --> 00:01:00,590 Similarly you can compare a variable with some string. 12 00:01:00,900 --> 00:01:09,500 In our case which string how it is really important to not forget on spaces Otherwise you will have 13 00:01:09,510 --> 00:01:12,020 problem running that comparison. 14 00:01:12,120 --> 00:01:19,290 It may feel strange to put spaces next to brackets and variables especially if you know some other programming 15 00:01:19,290 --> 00:01:26,370 language where a condition of writing is not space sensitive but by creating scripts and practicing 16 00:01:26,430 --> 00:01:29,910 you quickly get used to it. 17 00:01:30,030 --> 00:01:38,310 We said that for string comparison we are using a variable name inside double quotation mark why we 18 00:01:38,310 --> 00:01:46,920 do that because if you don't do that and some string is not defined or empty you get an error message 19 00:01:47,340 --> 00:01:52,290 which would lead to not properly working script. 20 00:01:52,750 --> 00:01:59,020 But in beshe there is a way how to not use double quotation marks. 21 00:01:59,020 --> 00:02:02,940 It is by using double square brackets. 22 00:02:03,030 --> 00:02:10,540 And should be mention that this is not vitally whilst most people are using single square brackets and 23 00:02:10,540 --> 00:02:18,070 double quotation marks around variables but the board ways are correct and it is up to you would you 24 00:02:18,070 --> 00:02:19,580 prefer. 25 00:02:19,580 --> 00:02:28,300 Also if you use double square brackets you can also use quotation marks around the variables. 26 00:02:28,300 --> 00:02:30,250 There is no issue with that. 27 00:02:30,450 --> 00:02:36,290 Only you would get slightly larger called. 28 00:02:36,560 --> 00:02:47,750 We can also test if a string is empty by using dataset or an open and when using Desch is that it is 29 00:02:47,750 --> 00:02:51,650 written through if string is empty. 30 00:02:51,650 --> 00:02:58,970 When we use Desch M it is written through in a case that string is not empty. 31 00:02:59,750 --> 00:03:08,850 And of course as for comparing two strings we can use double square brackets instead of single and in 32 00:03:08,850 --> 00:03:15,000 such case we don't need to have double quotation marks around variables. 33 00:03:15,000 --> 00:03:18,040 It is again up to you what do you prefer. 34 00:03:18,450 --> 00:03:27,830 Mostly it is use single square to break it with the double quotation marks around var.. 35 00:03:27,850 --> 00:03:34,300 We can also alphabetically compare two strings if you want to compare alphabetically. 36 00:03:34,480 --> 00:03:37,100 We need to use doubles square brackets. 37 00:03:37,240 --> 00:03:41,460 You don't have a choice between double and single square brackets. 38 00:03:43,530 --> 00:03:51,900 For string comparison we are also using a wildcard in regular expressions but those two techniques are 39 00:03:51,900 --> 00:03:52,980 quite complex. 40 00:03:52,980 --> 00:03:58,050 So I will tell you more about them in separate lecture. 41 00:03:58,090 --> 00:04:04,810 Now we see that for string comparison there are some rules which might seem complicated. 42 00:04:05,110 --> 00:04:08,170 The best way how to remember them is to practice. 43 00:04:08,290 --> 00:04:11,480 So let's write some script to see it in action.