1 00:00:01,320 --> 00:00:03,330 So now let's actually click on this. 2 00:00:03,360 --> 00:00:05,190 Start of the loop button here. 3 00:00:05,460 --> 00:00:07,380 As you can see it says 15. 4 00:00:07,650 --> 00:00:08,130 OK. 5 00:00:08,250 --> 00:00:12,210 So it is actually executing this up do I do 15 times. 6 00:00:12,450 --> 00:00:17,550 So what's the difference between a loop and a do while loop the loop. 7 00:00:17,690 --> 00:00:24,900 You're actually sure that it's going to actually first of all specify that whether this condition is 8 00:00:24,900 --> 00:00:28,990 true or not until it is less than or equal to number 10. 9 00:00:29,190 --> 00:00:33,870 And then it can actually go inside this y loop and then it's going to execute these lines of code. 10 00:00:33,860 --> 00:00:34,760 Here for example. 11 00:00:34,980 --> 00:00:41,140 But do a loop First of all it can actually do these lines of code inside of these curly braces. 12 00:00:41,270 --> 00:00:42,000 OK. 13 00:00:42,030 --> 00:00:46,290 First it's going to actually do these lines of code and then it's going to check the condition. 14 00:00:46,320 --> 00:00:46,820 Why. 15 00:00:46,950 --> 00:00:49,950 Why is less than or equal to number 15. 16 00:00:49,950 --> 00:00:57,420 So in Duvel loop you are sure that your codes inside the DO statement is going to be executed at least 17 00:00:57,420 --> 00:00:58,380 once. 18 00:00:58,690 --> 00:00:59,050 OK. 19 00:00:59,070 --> 00:01:01,270 And then it can actually check the condition. 20 00:01:01,610 --> 00:01:02,050 OK. 21 00:01:02,130 --> 00:01:06,040 First it's going to do these lines of code and then it's going to check the condition. 22 00:01:06,060 --> 00:01:08,220 And then again it's going actually. 23 00:01:08,280 --> 00:01:13,480 And then if the condition is true it is going to again do these lines of code inside of these two statements 24 00:01:13,530 --> 00:01:15,740 and then it's going to again take that condition. 25 00:01:15,960 --> 00:01:21,900 And then if the condition here is again true if the Y is less than or equal to number 15 again it's 26 00:01:21,900 --> 00:01:27,610 going to actually go inside of this statement and then executed is of course OK. 27 00:01:27,780 --> 00:01:33,870 But invite loop First of all it's going to actually check the condition whether the eye is less than 28 00:01:33,870 --> 00:01:37,870 or equal to number 10 if the eye is less than or equal to number 10. 29 00:01:37,890 --> 00:01:41,870 It's going to actually execute these lines of code inside of this white loop. 30 00:01:42,060 --> 00:01:48,240 But if the eye is not less than or equal to number 10 it is not going to actually execute these lines 31 00:01:48,240 --> 00:01:48,870 of code here. 32 00:01:48,930 --> 00:01:49,500 OK. 33 00:01:49,560 --> 00:01:51,630 So here for example if we actually change. 34 00:01:51,720 --> 00:01:57,750 So here for example if we actually to change the value of this value valuable to for example number 35 00:01:58,140 --> 00:02:03,910 as 40 as you can see the value of this value variable is now 40. 36 00:02:04,200 --> 00:02:04,660 OK. 37 00:02:04,740 --> 00:02:09,900 And here I am actually checking that video is the value of the value variable is less than or equal 38 00:02:09,900 --> 00:02:10,920 to number 15. 39 00:02:11,070 --> 00:02:13,440 So let's actually run our project and see what happens. 40 00:02:13,440 --> 00:02:15,430 So now let's actually click on this. 41 00:02:15,450 --> 00:02:20,160 Start the loop button here as you can see it says the number 40. 42 00:02:20,190 --> 00:02:27,720 So OK as you can see the value of this variable is 40 and then it is actually executing these lines 43 00:02:27,720 --> 00:02:30,820 of code inside of this statement here. 44 00:02:30,870 --> 00:02:32,660 And then he's going to check the condition. 45 00:02:32,880 --> 00:02:33,640 OK. 46 00:02:33,960 --> 00:02:41,070 So hopefully that makes sense and let texturally comment out these lines of code here and let me actually 47 00:02:41,190 --> 00:02:44,890 again show you another important point about the value. 48 00:02:45,450 --> 00:02:46,260 OK. 49 00:02:46,590 --> 00:02:52,170 So as you can see here first I what we are actually creating an arm variable of type Integer. 50 00:02:52,260 --> 00:02:58,030 And then I see that you are creating a wide loop and then if are checking that the are you ready and 51 00:02:58,040 --> 00:03:02,240 the value of the variable is less than or equal to number 10. 52 00:03:02,430 --> 00:03:06,430 And that inside of this white statement you are actually putting in some lines of code. 53 00:03:06,570 --> 00:03:07,020 OK. 54 00:03:07,020 --> 00:03:13,110 So as you can see here I am actually putting this A-plus plus here and this means that after each execution 55 00:03:13,140 --> 00:03:18,730 of these of-I loop it is going to actually increase the value of the variable by 1. 56 00:03:18,870 --> 00:03:23,880 Ok so now let's let's actually comment on this line of code here and let's run that project and see 57 00:03:23,880 --> 00:03:24,550 what happens. 58 00:03:24,630 --> 00:03:28,160 So now as you can see our application is running on the emulator. 59 00:03:28,470 --> 00:03:33,050 So if I actually click on this start the loop button here. 60 00:03:33,180 --> 00:03:34,370 Let's see what happens. 61 00:03:34,410 --> 00:03:34,840 OK. 62 00:03:34,890 --> 00:03:42,110 An important point here I want to actually show you that you need to actually always consider in your 63 00:03:42,190 --> 00:03:43,960 heart in all of your projects. 64 00:03:44,040 --> 00:03:49,860 So let's just actually click on this start the loop button here as you can see nothing happened but 65 00:03:49,920 --> 00:03:55,000 it is actually doing tons of are actually calculations here. 66 00:03:55,110 --> 00:03:58,170 And then this can actually crash our application. 67 00:03:58,170 --> 00:04:00,170 So let's wait a little time. 68 00:04:00,550 --> 00:04:05,130 And as you can see here now he's going to say our application is not responding. 69 00:04:05,400 --> 00:04:11,890 And then it is going to crash and then I want to actually show you of why this crash happened. 70 00:04:11,910 --> 00:04:16,610 So as you can see here now it is an error app isn't responding. 71 00:04:16,650 --> 00:04:19,380 Do you want to close it OK. 72 00:04:20,290 --> 00:04:21,760 So the application is crashed. 73 00:04:21,820 --> 00:04:23,950 So what happened as you can see here. 74 00:04:24,220 --> 00:04:27,630 First of all I actually created a value of type Integer. 75 00:04:27,850 --> 00:04:34,270 And then here inside and then here inside of the apprentice's of this why loop I specified until the 76 00:04:34,360 --> 00:04:37,740 right is less than or equal to number 10. 77 00:04:37,780 --> 00:04:43,850 So here as you can see when I actually created this variable I assigned a value to my value but number 78 00:04:43,880 --> 00:04:44,790 zero. 79 00:04:44,860 --> 00:04:51,880 And here I am actually specifying specifying a condition in order to actually execute a while loop until 80 00:04:51,880 --> 00:04:54,490 the is less than or equal to number 10. 81 00:04:54,490 --> 00:04:57,840 So as you can see here number 0 is less than the number 10. 82 00:04:58,180 --> 00:05:04,840 And then inside of this one loop I am actually saying to the start that said text plus are two double 83 00:05:04,840 --> 00:05:05,520 quotes here. 84 00:05:05,650 --> 00:05:06,140 OK. 85 00:05:06,340 --> 00:05:13,900 And I actually commented out this line of code here and it says increase the value of this variable 86 00:05:13,900 --> 00:05:17,320 by one after each execution of this while loop. 87 00:05:17,320 --> 00:05:23,210 So now when I actually comment a commented out this line of code it is now actually the executive in 88 00:05:23,500 --> 00:05:25,490 this wild move forever. 89 00:05:25,840 --> 00:05:26,330 OK. 90 00:05:26,410 --> 00:05:32,710 It is not going to stop this why loop because we actually didn't specify what is going to happen to 91 00:05:32,710 --> 00:05:37,440 this or to the value of this variable after each execution of this while loop. 92 00:05:37,590 --> 00:05:42,880 If you are just saying until the it is less than or equal to number 10 please execute this line of code 93 00:05:42,880 --> 00:05:43,310 here. 94 00:05:43,630 --> 00:05:47,690 And that is going to actually do what we actually specify here. 95 00:05:47,950 --> 00:05:48,390 OK. 96 00:05:48,400 --> 00:05:53,040 So we need to be explicit when we actually talk to our computer. 97 00:05:53,050 --> 00:05:57,050 It is going to actually executive this line of code here forever. 98 00:05:57,320 --> 00:05:57,720 OK. 99 00:05:57,760 --> 00:06:00,780 So we need to actually put this line of code here. 100 00:06:00,910 --> 00:06:08,700 Plus plus in order to tell the computer please increase the number of the value of this valuable by 101 00:06:08,710 --> 00:06:12,490 one after each execution of this while loop. 102 00:06:12,490 --> 00:06:18,400 So hopefully that makes sense and if we actually run my project again let's see what happens. 103 00:06:18,400 --> 00:06:20,100 So now let's actually click on this. 104 00:06:20,140 --> 00:06:21,930 Start the loop button here. 105 00:06:22,300 --> 00:06:24,350 As you can see it says number 10. 106 00:06:24,400 --> 00:06:27,260 So as you can see it is actually the cutest. 107 00:06:27,350 --> 00:06:30,210 This Alwi loop ten times. 108 00:06:30,250 --> 00:06:30,990 OK. 109 00:06:31,330 --> 00:06:33,430 So hopefully that makes sense. 110 00:06:33,430 --> 00:06:39,150 So now let's actually go inside this content underline minute example and let's actually try again. 111 00:06:39,590 --> 00:06:42,500 Another actually takes you here. 112 00:06:42,550 --> 00:06:46,310 Now I want to actually show you the value of the variable. 113 00:06:46,330 --> 00:06:49,240 So after the execution of the loops. 114 00:06:49,570 --> 00:06:52,410 So let's actually double click on this component. 115 00:06:52,570 --> 00:07:01,510 So for the text I can just type in the value of pi and for ID I can just type in T S T Y. 116 00:07:02,110 --> 00:07:02,780 OK. 117 00:07:03,160 --> 00:07:10,420 So let's go back and say this main activity that Java here and now I want to actually first of all we 118 00:07:10,420 --> 00:07:17,590 need to actually create an object of this test class takes through the XTi. 119 00:07:18,040 --> 00:07:19,200 All right. 120 00:07:19,720 --> 00:07:27,250 And then I put an assignment operator here and then I need to actually cast this object to our text 121 00:07:27,250 --> 00:07:28,150 view object. 122 00:07:28,150 --> 00:07:36,840 And here I can just type in find view by id r that Id Dot T XTi by OK. 123 00:07:36,930 --> 00:07:44,940 So here as you can see decompiler I actually automatically put this final Q-Bot here in order to make 124 00:07:44,940 --> 00:07:51,100 this object a constant because it says well we actually assign a value. 125 00:07:51,510 --> 00:07:57,650 Once we actually assign a value to this at the start we cannot actually change that value. 126 00:07:57,870 --> 00:08:03,730 And it is actually right because whenever we actually refer to the name of this variable to use the 127 00:08:03,730 --> 00:08:10,770 start we are just you are just assigning a specific value to that variable at the start. 128 00:08:10,770 --> 00:08:11,990 That said text. 129 00:08:12,150 --> 00:08:19,390 Ok we cannot change this at runtime we cannot change this to another value because. 130 00:08:19,530 --> 00:08:21,470 OK because this is a constant. 131 00:08:21,480 --> 00:08:23,060 OK so hopefully that makes sense. 132 00:08:23,160 --> 00:08:25,860 So now let's actually refer to the name of this t XTi. 133 00:08:25,890 --> 00:08:30,380 I object that said text added inside the parenthesis. 134 00:08:30,390 --> 00:08:34,950 I can just refer to the name of this variable plus two double calls. 135 00:08:34,980 --> 00:08:37,530 So let's actually not project and see what happens. 136 00:08:37,530 --> 00:08:38,440 OK everyone. 137 00:08:38,490 --> 00:08:42,260 Now as you can see our application is running on this emulator. 138 00:08:42,360 --> 00:08:43,920 So let's actually click on this. 139 00:08:43,920 --> 00:08:51,710 Start the loop bottom here and as you can see here it is actually executing this way look 10 times and 140 00:08:51,710 --> 00:08:57,570 that it is actually outputting the value of this valuable to this great number 11. 141 00:08:57,660 --> 00:08:58,560 OK. 142 00:08:59,010 --> 00:09:00,690 So hopefully that makes sense.