1 00:00:02,310 --> 00:00:08,220 All right, let's finish up the concept of function by talking about what is called the return keyword. 2 00:00:08,550 --> 00:00:08,850 All right. 3 00:00:08,850 --> 00:00:12,220 So before we talk about the return keyword, let's solve this exercise. 4 00:00:12,240 --> 00:00:14,380 So let me comment out this one here. 5 00:00:14,400 --> 00:00:16,079 I don't see many console.log. 6 00:00:16,110 --> 00:00:18,010 Or I can I can comment on this one. 7 00:00:18,030 --> 00:00:18,560 Okay. 8 00:00:18,570 --> 00:00:21,140 So the function goes like this one we can use. 9 00:00:21,150 --> 00:00:22,290 Let me change to use. 10 00:00:22,290 --> 00:00:23,460 I mean, function declaration. 11 00:00:23,460 --> 00:00:26,580 So function function. 12 00:00:26,580 --> 00:00:31,140 And then I say multiply, multiply numbers. 13 00:00:31,170 --> 00:00:37,170 Now my square bracket and my function body here and here, it takes three things, right? 14 00:00:37,170 --> 00:00:41,790 I can say A, B and C in a name here. 15 00:00:41,790 --> 00:00:43,020 Anybody here can see number one. 16 00:00:43,020 --> 00:00:44,010 Number two and I'm three. 17 00:00:44,010 --> 00:00:44,760 It's up to you. 18 00:00:44,880 --> 00:00:48,720 So I will declare variable counts or let end of this one go. 19 00:00:48,960 --> 00:00:56,460 So a result is equal to A, times B, times C. 20 00:00:56,610 --> 00:01:03,150 Now when I call the function multiply num numbers are pass in three things, right? 21 00:01:03,150 --> 00:01:07,380 Pass in them passing one, two and three meaning. 22 00:01:08,310 --> 00:01:10,110 And let me console.log the results here. 23 00:01:10,140 --> 00:01:10,920 I didn't do it. 24 00:01:10,950 --> 00:01:12,510 I'm going to look at the results here. 25 00:01:14,150 --> 00:01:14,610 Okay. 26 00:01:14,630 --> 00:01:21,200 So here A is one, B is two and C is three. 27 00:01:21,320 --> 00:01:26,300 If I console.log it to be one times two, some three, what would be the answer? 28 00:01:26,450 --> 00:01:31,880 One times two is what is two times three six? 29 00:01:32,090 --> 00:01:32,900 Let's try. 30 00:01:33,800 --> 00:01:34,880 Let's save it. 31 00:01:35,510 --> 00:01:37,330 Indeed, we have six. 32 00:01:37,340 --> 00:01:39,170 That is the solution to this question. 33 00:01:39,940 --> 00:01:40,540 Okay. 34 00:01:40,570 --> 00:01:45,460 So last part you talk about is what you call the return keyword. 35 00:01:45,910 --> 00:01:50,200 So let's use this one or let's use this one to explain more. 36 00:01:50,230 --> 00:01:52,030 Okay, let me copy this one here. 37 00:01:52,030 --> 00:01:59,590 Let me comment out and let me comment out this one also and let me paste this function here as before. 38 00:01:59,800 --> 00:02:00,100 Okay. 39 00:02:00,100 --> 00:02:04,030 So let me come in here and call this one the return. 40 00:02:05,170 --> 00:02:11,290 Keyword return after this one, then you'll be a guru when it comes to function creating. 41 00:02:12,000 --> 00:02:12,550 Okay. 42 00:02:12,970 --> 00:02:15,970 So what is the purpose of the return key? 43 00:02:16,150 --> 00:02:17,290 We need a function. 44 00:02:17,470 --> 00:02:19,720 So at this time, right now. 45 00:02:20,110 --> 00:02:27,000 Well, the purpose or the only way this function is doing is that it's taking in some dynamic value. 46 00:02:27,010 --> 00:02:28,470 Make it more easy to read. 47 00:02:28,480 --> 00:02:29,260 Let me see. 48 00:02:29,860 --> 00:02:33,330 Three +47. 49 00:02:33,610 --> 00:02:34,090 We can all. 50 00:02:34,090 --> 00:02:34,540 Really. 51 00:02:35,050 --> 00:02:35,530 Okay. 52 00:02:38,470 --> 00:02:39,280 Let me save it. 53 00:02:40,280 --> 00:02:40,760 Yeah. 54 00:02:41,210 --> 00:02:49,880 So what this function is doing is that, well, it has sort of problems about I mean, we have to centralize 55 00:02:49,880 --> 00:02:57,140 our code in one place, but the governance here is that this function in time, I call this function, 56 00:02:57,380 --> 00:03:00,830 I can call it many times, as many times as I want. 57 00:03:00,860 --> 00:03:01,640 Let's see. 58 00:03:02,030 --> 00:03:04,240 We see we have seven, seven here. 59 00:03:04,250 --> 00:03:05,750 But here comes the problem. 60 00:03:05,960 --> 00:03:12,380 Let's say that I want to display the result of my function into the page here. 61 00:03:13,780 --> 00:03:14,860 But don't worry. 62 00:03:14,860 --> 00:03:18,910 We haven't talked about Dom manipulation, so spare me with that. 63 00:03:19,870 --> 00:03:24,850 I'm going to give you some some scenarios why this function is not performing the way we want it. 64 00:03:25,570 --> 00:03:27,010 That's the scenario, number one. 65 00:03:27,250 --> 00:03:29,410 And also, what about say that? 66 00:03:29,410 --> 00:03:35,220 Oh, no, I don't want this play my result into the page, but instead I want to display it inside an 67 00:03:35,230 --> 00:03:35,950 elect. 68 00:03:36,160 --> 00:03:38,140 How can we do that? 69 00:03:38,650 --> 00:03:47,320 In that way, we need what is called the return keyword, because this function is not giving out anything. 70 00:03:47,740 --> 00:03:48,970 It just console.log in it. 71 00:03:49,150 --> 00:03:50,110 So there were ten. 72 00:03:50,110 --> 00:03:57,940 Key is used to exit a function and return a value to the caller. 73 00:03:58,600 --> 00:03:59,590 Here comes. 74 00:03:59,950 --> 00:04:04,750 So one point of return is it is used to exit a function. 75 00:04:05,200 --> 00:04:07,390 I would I would explain to you with code right now. 76 00:04:07,830 --> 00:04:08,200 Okay. 77 00:04:08,560 --> 00:04:17,170 And then if a value is present in the return, it is going to give out to the variable we assign a function 78 00:04:17,170 --> 00:04:17,560 to. 79 00:04:18,370 --> 00:04:22,870 The return keyword is essential for creating functions that return value. 80 00:04:22,880 --> 00:04:24,820 So this function is returning values. 81 00:04:24,910 --> 00:04:31,480 So without it, function will only be able to perform actions but not return values to the caller. 82 00:04:31,600 --> 00:04:37,240 This would limit the usefulness of a functions and make them much less powerful. 83 00:04:37,990 --> 00:04:40,690 So that's what we talk about right now, right? 84 00:04:40,870 --> 00:04:47,900 Because this function, even though it's doing some action, but it's not doing it's not more useful. 85 00:04:47,920 --> 00:04:50,260 That's why we tend to come in here. 86 00:04:50,680 --> 00:04:52,840 So here it comes. 87 00:04:52,870 --> 00:04:57,030 Now, instead of returning a console of this one here. 88 00:04:57,130 --> 00:05:01,960 Now you bring in the return keyword from JavaScript. 89 00:05:02,880 --> 00:05:06,630 And then what are we giving out or return from? 90 00:05:06,630 --> 00:05:08,550 This function is the result. 91 00:05:09,570 --> 00:05:13,650 So many that JavaScript runs our code line by line. 92 00:05:13,680 --> 00:05:16,170 If it gets here, first of all, declare a variable. 93 00:05:16,170 --> 00:05:22,530 And here you go to a line number eight where I have a variable called result and give me X plus Y, 94 00:05:22,530 --> 00:05:23,880 which is three plus seven. 95 00:05:23,880 --> 00:05:28,110 Let me remove this one from here and let me save it. 96 00:05:28,200 --> 00:05:33,180 Now, see that we have nothing here, even though we have the risk, but because we have removed the 97 00:05:33,180 --> 00:05:39,750 console.log and then we are using the return keyword, how are we going to get the result here? 98 00:05:40,110 --> 00:05:40,920 Here comes. 99 00:05:41,160 --> 00:05:45,330 So here we have given the result to return. 100 00:05:45,540 --> 00:05:54,630 It means that when you call it a function, we have the value inside the return keyword with the function. 101 00:05:55,290 --> 00:05:59,610 So to anytime, use a function, use a return keyword. 102 00:05:59,730 --> 00:06:04,560 Again, when you call it, you assign the result to a variable. 103 00:06:04,590 --> 00:06:06,060 You can see that led. 104 00:06:06,300 --> 00:06:13,950 Now we can say and so is equal to now because of the return keyword. 105 00:06:14,460 --> 00:06:19,200 This one represents the result coming out from this function. 106 00:06:19,380 --> 00:06:23,250 So now behind the scene, this is seven, right? 107 00:06:23,250 --> 00:06:30,780 And it's now in the variable of and so I can take this variable and use it wherever I want. 108 00:06:31,020 --> 00:06:32,520 I can console.log it. 109 00:06:32,880 --> 00:06:36,750 I can display it here and wherever I want display I can use it. 110 00:06:36,750 --> 00:06:41,040 So if I console.log the answer. 111 00:06:42,090 --> 00:06:42,810 Check it out. 112 00:06:43,020 --> 00:06:45,240 Now, you see, I have seven. 113 00:06:46,380 --> 00:06:47,250 I have seven. 114 00:06:47,250 --> 00:06:48,540 That is 40. 115 00:06:48,540 --> 00:06:54,420 Or if I don't want to call it here, I can use a method called select. 116 00:06:54,510 --> 00:06:56,820 I let that display something in the browser. 117 00:06:57,390 --> 00:07:00,360 Okay, so here I select and then my answer. 118 00:07:01,280 --> 00:07:02,450 If I save it. 119 00:07:02,480 --> 00:07:06,950 Now, you see that we have taken the result and display it here. 120 00:07:07,970 --> 00:07:15,560 Now our function is more reusable because now we can take this function and then display the result 121 00:07:15,560 --> 00:07:17,000 any way I want. 122 00:07:17,960 --> 00:07:23,930 Let's talk about the exit, anywhere or inside, any function. 123 00:07:24,290 --> 00:07:32,720 If it sees return keyword it exit meaning is top the the function or the logic inside of a function. 124 00:07:32,930 --> 00:07:44,480 So now to prove to you let's console.log something here console dot log let's say function code like 125 00:07:44,480 --> 00:07:45,080 this one. 126 00:07:45,620 --> 00:07:47,720 So if I save it, have a look. 127 00:07:47,720 --> 00:07:48,830 Let me remove this console. 128 00:07:48,830 --> 00:07:49,130 Let me. 129 00:07:49,130 --> 00:07:49,760 Alexia. 130 00:07:51,330 --> 00:07:57,600 If I press the piece, I see what function call, because when I call this function, it is reading 131 00:07:57,600 --> 00:07:58,530 line by line. 132 00:07:58,620 --> 00:08:01,560 It gets here x plus x, which is five. 133 00:08:01,590 --> 00:08:02,300 Give it to this one. 134 00:08:02,310 --> 00:08:03,330 Go to console.log. 135 00:08:03,360 --> 00:08:07,890 That's why it has to be displayed here, because we have called a function here. 136 00:08:08,400 --> 00:08:12,120 So but let me say function. 137 00:08:12,540 --> 00:08:17,340 Let me say before before return keyword. 138 00:08:18,060 --> 00:08:19,080 Before retain. 139 00:08:19,080 --> 00:08:20,670 And then the same thing here. 140 00:08:21,830 --> 00:08:25,130 We're down here and say after ten. 141 00:08:25,280 --> 00:08:28,280 So when I save this one, we see that. 142 00:08:28,310 --> 00:08:29,660 Let me save this function. 143 00:08:30,350 --> 00:08:38,330 You can see that this one has called the first one, meaning the function before return has caught. 144 00:08:38,330 --> 00:08:39,200 But this one. 145 00:08:39,620 --> 00:08:44,730 You see that this one has been degraded, meaning this punch will never be called. 146 00:08:44,750 --> 00:08:47,960 As soon as it gets to this return, it exits. 147 00:08:47,990 --> 00:08:49,340 The function will not continue. 148 00:08:49,370 --> 00:08:51,250 That's why we couldn't call this one. 149 00:08:51,260 --> 00:08:57,590 But if I remove the return from here and save it, we see the two of them has been called. 150 00:08:57,650 --> 00:09:01,310 That's the purpose of a function, the return keyword.