1 00:00:00,210 --> 00:00:05,010 Hi everyone in this theater early on I'm going to talk about methods in Java. 2 00:00:05,010 --> 00:00:05,580 OK. 3 00:00:05,700 --> 00:00:08,850 So first we need to create a Java project. 4 00:00:08,850 --> 00:00:13,370 So just click on File New and then click on Java project. 5 00:00:13,380 --> 00:00:14,440 OK. 6 00:00:15,190 --> 00:00:22,380 And for the project name just type in here methods and then click on finish. 7 00:00:22,770 --> 00:00:25,700 So as you can see here our project is now created. 8 00:00:25,890 --> 00:00:27,640 So now we need a main class. 9 00:00:27,660 --> 00:00:28,330 OK. 10 00:00:28,380 --> 00:00:36,700 So just click on this as RC folder and then click on find new and then click on class. 11 00:00:36,730 --> 00:00:39,530 So for the class name just type in here. 12 00:00:39,700 --> 00:00:41,410 Meffert. 13 00:00:42,480 --> 00:00:43,300 OK. 14 00:00:43,630 --> 00:00:47,240 And for the package name we need a reverse domain here. 15 00:00:47,380 --> 00:00:55,180 Just type in here com dot your name dot project name OK. 16 00:00:55,590 --> 00:01:02,730 And for the modifiers to public and here to make sure that you check this checkbox here that says public 17 00:01:02,790 --> 00:01:04,220 static void main effect. 18 00:01:04,230 --> 00:01:04,810 OK. 19 00:01:04,950 --> 00:01:07,780 This is the starting point for running our Java code. 20 00:01:07,800 --> 00:01:08,390 OK. 21 00:01:08,520 --> 00:01:09,940 And then click on finish. 22 00:01:10,140 --> 00:01:13,340 So as you can see here our class is now created. 23 00:01:13,460 --> 00:01:21,660 OK so now let me actually delete this comment here and then in order to make this a little earlier Vider 24 00:01:21,780 --> 00:01:25,510 I just need to double click on the Smurfette Java tab here. 25 00:01:25,530 --> 00:01:26,000 OK. 26 00:01:26,010 --> 00:01:31,980 Our editor area is now much wider and we can write our codes inside the main method. 27 00:01:31,980 --> 00:01:32,460 OK. 28 00:01:32,550 --> 00:01:35,880 So I want to talk about methods in Java. 29 00:01:35,930 --> 00:01:46,170 OK so what are if it's a job or if it is a collection of statements that are grouped together to perform 30 00:01:46,380 --> 00:01:47,480 an operation. 31 00:01:47,600 --> 00:01:48,170 OK. 32 00:01:48,360 --> 00:01:55,880 You have been using methods in the previous tutorials like the main method that I told you about. 33 00:01:55,890 --> 00:01:56,440 OK. 34 00:01:56,580 --> 00:02:03,970 In this tutorial I'm going to show you what methods actually are and how you can create your own methods. 35 00:02:03,990 --> 00:02:04,610 OK. 36 00:02:04,830 --> 00:02:10,330 So our method is just a chunk of code that does a particular job. 37 00:02:10,430 --> 00:02:10,860 OK. 38 00:02:10,920 --> 00:02:14,700 But methods are set out in a certain way. 39 00:02:14,710 --> 00:02:18,530 You have a method header and I'm a fed body. 40 00:02:18,660 --> 00:02:26,910 The header is very you tell Java about what value you type if any the method will return OK and ain't 41 00:02:27,150 --> 00:02:29,370 value or double value etc.. 42 00:02:29,450 --> 00:02:37,070 OK as well as the return type you'll need a name for your method which also goes in the header. 43 00:02:37,110 --> 00:02:44,940 Ok you can pass values over to your methods and these go between a pair of round brackets. 44 00:02:44,950 --> 00:02:48,380 OK the method body is where your statement goes. 45 00:02:48,410 --> 00:02:52,210 OK in Suydam effort body you actually put your own statements. 46 00:02:52,250 --> 00:02:59,930 OK so first let me point out that you must always create your methods inside the class. 47 00:02:59,940 --> 00:03:00,620 OK. 48 00:03:00,810 --> 00:03:04,580 And you can not create your methods inside other methods. 49 00:03:04,700 --> 00:03:09,960 OK so for example you cannot create MFX inside the main method. 50 00:03:09,960 --> 00:03:13,480 OK so now let me give you some real examples. 51 00:03:13,510 --> 00:03:17,710 OK we cannot actually create methods inside other methods. 52 00:03:17,730 --> 00:03:20,820 OK we can only create methods inside the class. 53 00:03:20,860 --> 00:03:24,810 OK so inside the method class as you can see here. 54 00:03:25,290 --> 00:03:28,650 In between those curly braces this is our method class. 55 00:03:28,650 --> 00:03:31,610 Ok here I can actually create my own method. 56 00:03:31,740 --> 00:03:33,930 So I just need to type in here. 57 00:03:34,030 --> 00:03:41,220 Voit OK and the name of my Smurfette would be do something. 58 00:03:45,280 --> 00:03:51,820 OK and then at the end of my Meffert name I need to put in a pair of round brackets. 59 00:03:51,850 --> 00:03:52,360 OK. 60 00:03:52,360 --> 00:03:59,830 And then I need to open and close my Smurfette by using an opening curly brace followed by our closing 61 00:03:59,830 --> 00:04:00,580 curly brace. 62 00:04:00,580 --> 00:04:01,460 OK. 63 00:04:01,480 --> 00:04:04,710 So as you can see here are my fate is now created. 64 00:04:04,750 --> 00:04:05,190 OK. 65 00:04:05,290 --> 00:04:07,320 So what does this avoid hear me. 66 00:04:07,330 --> 00:04:07,710 OK. 67 00:04:07,750 --> 00:04:13,250 So here this void here is the return value of my method. 68 00:04:13,420 --> 00:04:21,690 OK so first in order to create your Mefford you need to actually specify the return value of your method. 69 00:04:21,940 --> 00:04:26,570 So as you can see here the return value of my method is void. 70 00:04:26,630 --> 00:04:27,290 OK. 71 00:04:27,490 --> 00:04:31,050 This means that this Smurfette return is enough. 72 00:04:31,110 --> 00:04:36,150 Ok this void here means that my method is going to return nothing. 73 00:04:36,340 --> 00:04:39,200 And my method is going to actually to just do something. 74 00:04:39,220 --> 00:04:44,540 Ok this type of method is the most simplest type of method. 75 00:04:44,560 --> 00:04:48,440 So as you can see here I must give my method a name. 76 00:04:48,620 --> 00:04:51,210 OK this is the name of my method do something. 77 00:04:51,430 --> 00:04:56,930 And then at the end of my method I need to put in a pair of round brackets. 78 00:04:56,980 --> 00:05:04,960 After that I need to open and close my Smurfette by using an opening curly brace followed by our closing 79 00:05:04,960 --> 00:05:05,580 curly brace. 80 00:05:05,610 --> 00:05:09,400 OK so this is how you create MFL in Java. 81 00:05:09,400 --> 00:05:10,080 OK. 82 00:05:10,330 --> 00:05:13,460 And then inside them F-ed I can't put my statements. 83 00:05:13,520 --> 00:05:17,550 So inside these two curly braces I can put my own statements. 84 00:05:17,590 --> 00:05:17,990 OK. 85 00:05:18,010 --> 00:05:23,670 So for example now I just want to output the value of some text to the console. 86 00:05:23,680 --> 00:05:24,240 OK. 87 00:05:24,490 --> 00:05:26,140 So I just need to type in here. 88 00:05:26,230 --> 00:05:37,720 System that out that line and then inside the prentices I need to put in two double quotes and and then 89 00:05:38,200 --> 00:05:40,950 inside the double quotes I can put in my text. 90 00:05:40,960 --> 00:05:41,780 OK. 91 00:05:42,310 --> 00:05:47,680 So this text comes from the do something Meffert. 92 00:05:47,740 --> 00:05:48,810 OK. 93 00:05:49,210 --> 00:05:54,710 So now if you on my project as you can see here it's going to show us nothing. 94 00:05:54,880 --> 00:05:59,030 We need to actually call our Mefford from the main method. 95 00:05:59,080 --> 00:05:59,960 OK. 96 00:06:00,130 --> 00:06:06,620 That's the importance of the main method the main method is the starting point for running our Java 97 00:06:06,640 --> 00:06:07,140 code. 98 00:06:07,170 --> 00:06:07,590 OK. 99 00:06:07,630 --> 00:06:13,390 Without this main effect we cannot actually run or execute our Java code. 100 00:06:13,420 --> 00:06:14,000 OK. 101 00:06:14,230 --> 00:06:20,150 So inside the main method OK I just need to refer to the name of our method. 102 00:06:20,200 --> 00:06:23,160 OK so the name of our method is do something. 103 00:06:23,200 --> 00:06:25,930 Ok so I just need to refer to this name. 104 00:06:26,170 --> 00:06:30,180 So I need to type in here do some finish. 105 00:06:30,580 --> 00:06:31,090 OK. 106 00:06:31,150 --> 00:06:38,080 And then at the end of my Smurfette name I need to put a pair of round brackets. 107 00:06:38,080 --> 00:06:38,670 OK. 108 00:06:38,800 --> 00:06:41,560 And then at the end I need to put in a semicolon. 109 00:06:41,860 --> 00:06:42,370 OK. 110 00:06:42,370 --> 00:06:45,270 So as you can see here it's now showing us an error. 111 00:06:45,280 --> 00:06:45,920 OK. 112 00:06:46,180 --> 00:06:53,980 So first let me point out that in order to make the eclipse happy for now just put the static keyword 113 00:06:54,070 --> 00:06:56,450 at the start of your Meffert creation. 114 00:06:56,470 --> 00:06:57,100 OK. 115 00:06:57,160 --> 00:07:00,230 Static void do something. 116 00:07:00,240 --> 00:07:07,120 OK so I'll talk more about this static or later but for now make sure that you put the static keyword 117 00:07:07,330 --> 00:07:09,830 before your method creation's. 118 00:07:09,850 --> 00:07:10,520 OK. 119 00:07:10,960 --> 00:07:13,910 So as you can see here the error is now gone. 120 00:07:13,960 --> 00:07:19,400 So if I run my project now as you can see it outputs this value to the console. 121 00:07:19,510 --> 00:07:22,440 This text comes from the do something method. 122 00:07:22,470 --> 00:07:28,140 Ok this text is the result of execution of this line of code here. 123 00:07:28,390 --> 00:07:28,920 OK. 124 00:07:29,020 --> 00:07:35,290 And in line 9 as you can see inside the main method I actually called this method. 125 00:07:35,350 --> 00:07:35,980 OK. 126 00:07:36,100 --> 00:07:38,520 So first of and I actually ran my project. 127 00:07:38,720 --> 00:07:41,170 It's gonna execute this main effect. 128 00:07:41,170 --> 00:07:41,630 OK. 129 00:07:41,710 --> 00:07:48,200 And then inside the main effect I actually referred to the name of our method to something and that 130 00:07:48,220 --> 00:07:55,420 it's going to actually go inside the do something method and then it's going to execute this line of 131 00:07:55,420 --> 00:07:56,160 code. 132 00:07:56,230 --> 00:08:00,610 And as you can see here this is the value that is output to the console OK. 133 00:08:00,610 --> 00:08:02,800 Now let me give you another example. 134 00:08:02,800 --> 00:08:03,260 OK. 135 00:08:03,310 --> 00:08:06,420 So first I need to put in the static keyboard. 136 00:08:06,430 --> 00:08:07,000 OK. 137 00:08:07,000 --> 00:08:08,120 Static. 138 00:08:08,710 --> 00:08:13,880 And then I need to specify the return type of my method. 139 00:08:13,930 --> 00:08:14,650 OK. 140 00:08:14,800 --> 00:08:17,280 So the return type of My effect is void. 141 00:08:17,560 --> 00:08:18,150 OK. 142 00:08:18,430 --> 00:08:21,690 And then I need to give my method a name. 143 00:08:21,730 --> 00:08:22,100 OK. 144 00:08:22,180 --> 00:08:27,520 So the name of my method would be multiply two numbers. 145 00:08:28,150 --> 00:08:28,740 OK. 146 00:08:28,840 --> 00:08:36,130 So this is the name of our my first and then at the end of our Meffert name we need to put in a pair 147 00:08:36,130 --> 00:08:38,030 of round brackets. 148 00:08:38,290 --> 00:08:46,090 And then I need to open and close my Meffert by using an opening curly brace followed by our closing 149 00:08:46,090 --> 00:08:47,910 curly brace. 150 00:08:47,930 --> 00:08:51,040 So as you can see here are my fate is now created. 151 00:08:51,050 --> 00:08:51,510 OK. 152 00:08:51,560 --> 00:08:55,510 So now I can putting my statements inside this method. 153 00:08:55,550 --> 00:08:56,200 OK. 154 00:08:56,540 --> 00:08:59,780 So now I want to create some variables here. 155 00:08:59,810 --> 00:09:03,160 So the first variable is it a. 156 00:09:03,470 --> 00:09:07,580 And then I can assign a value to my variable for example number two. 157 00:09:08,030 --> 00:09:13,850 And the second variable is in B and I can assign another value to the Suadi. 158 00:09:13,850 --> 00:09:21,050 But for example number 6 and here I want to create another variable in order to sort of multiplication 159 00:09:21,080 --> 00:09:22,630 of these two numbers. 160 00:09:22,640 --> 00:09:22,990 OK. 161 00:09:23,000 --> 00:09:30,740 So here I just need to refer to the name of my evaluable multiplied by B OK. 162 00:09:31,040 --> 00:09:33,780 And then I need to put in a semicolon at the end of my statement. 163 00:09:33,810 --> 00:09:34,410 OK. 164 00:09:34,640 --> 00:09:39,890 And here I want to output the result to the Katsulas system that's out. 165 00:09:39,890 --> 00:09:41,120 That's princeling. 166 00:09:41,570 --> 00:09:48,280 And then inside Apprentice's and then inside the apprentice's I just need to refer to the result. 167 00:09:48,510 --> 00:09:51,690 And then at the end of my statement I need to put in a semi-colon.