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All right, here goes coding challenge number two, 2

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which is gonna be all about arrays. 3

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And in this one, 4

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we're gonna go back to the tip calculator 5

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that we built in the previous section. 6

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And we're still using the same rules as before. 7

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So we tip 15% of the bill value, if it's between 50 and 300. 8

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And if the value is different, so outside of this range, 9

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the tip is 20%. 10

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And so here are your tasks. 11

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First, write a function called calcTip, 12

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which takes any bill value as an input, 13

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and returns the corresponding tip. 14

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And so that's gonna be based on the rules 15

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that I just mentioned. 16

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And to do this, you can actually check out the code 17

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from the first tip calculator challenge 18

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that we did in the last section. 19

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So you can copy the code there. 20

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Or if you want, you can also code this from scratch, 21

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just to remember how to do it. 22

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And now in number two, we're finally gonna use arrays. 23

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So here, we're gonna create an array called bills, 24

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which will contain the test data that we have down here. 25

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So these are the three bill values 26

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for which we want to calculate the tips. 27

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And so that's what we do in point number three. 28

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So here, we create an array called tips, 29

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which will contain the tip value 30

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for each of the three bills. 31

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And this is where we're gonna use the calcTip function 32

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that we created before. 33

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So that's the basic challenge. 34

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And if you wanna take it one step further, 35

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you can even take the bonus question. 36

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So number four here, 37

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in which I ask you to create an array called total, 38

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which will have the total values. 39

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So that's the bill plus the tip. 40

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So I hope this one isn't too hard. 41

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Basically, it's similar to one of the examples actually, 42

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that we did in one of the lectures about the arrays. 43

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And once again, 44

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I also have a hint to help you solving this one. 45

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But if you want to try it on your own without the hint 46

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then pause video now, and good luck. 47

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But if you want to hint, 48

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well, then here it goes. 49

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So remember that an array needs a value in each position. 50

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But that value 51

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can actually be the returned value of a function. 52

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So as an array value, 53

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you can basically just call a function. Alright. 54

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And again, that is similar 55

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to something that we did in one of the array lectures. 56

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So pause the video now, 57

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and I see you with my solution in a second. 58

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Okay, and I'm gonna start by creating the calcTip function. 59

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And I'm gonna start doing it with a function expression. 60

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So this one will receive a bill as an input, 61

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I believe, I think, 62

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yeah, so calcTip takes any bill as an input. 63

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So let's simply call it bill. 64

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And then what we want to return is the tip. 65

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And here I'm gonna write the exact same code 66

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as we did in the other challenge. 67

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So there's no need to explain it all again, 68

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it would just be a waste of time. 69

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So if the bill value is between 50 and 300, 70

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so less or equal than 300. 71

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And here we're using the ternary operator, 72

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then return the bill value, times zero point 15. 73

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So that's 15%. 74

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And otherwise, it should be 20%. 75

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Okay, so the result of this ternary operator here 76

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will be one of these values. 77

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So either bill times point 15 or times point two. 78

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And so that's gonna be the result of this operator. 79

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And so that's what this function will return. 80

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If you prefer the arrow function, we can also do that. 81

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So const calcTip equal bill. 82

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And now we can omit the return keyword 83

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and do it all in one nice line. 84

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So now you just have to choose which one you like better. 85

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And I will just for the sake of readability. 86

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Keep the first one there. Okay. 87

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But if you prefer the arrow function, 88

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you can just use this one. Great. 89

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So number two is to simply create a bills array 90

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with these three values. 91

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So bills 125, five five five and 44. 92

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So that was easy. 93

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And now we will create an array tips, 94

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which will contain the tip value for each bill. 95

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So, let's do that. 96

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And now this is similar to what we did previously 97

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with calculating the ages. 98

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So we are going to create an array, 99

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and then each position will be the function call to calcTip. 100

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So we want to calc the tip with bills at position zero. 101

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Then at position one, we want to calculate bills. 102

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Or we actually want to calculate tips based on bills 103

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on position one, and then on position two. And that's it. 104

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So let's log both the bills 105

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and the tips to the console here. 106

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And that gives us tips is not defined. 107

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So here, it should be tips. 108

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So usually when I have an array, 109

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I like to give it a plural name, 110

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like here bills and here tips. 111

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So because it's multiple values, 112

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so now that should work. 113

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And yeah, so these were the three tips that were calculated. 114

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And of course, you could have created separate values, 115

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or actually separate variables 116

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for each of these function calls, 117

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like tip one equals calcTip with bills, zero, 118

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something like this. 119

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And then tip two and tip three. 120

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And then you could have created 121

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like an array with tip one, tip two and tip three. 122

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Okay, so something like this. 123

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But my idea was to actually do it like this, 124

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because then we don't have to create 125

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all these extra variables. So that's a lot cleaner. 126

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Later on in the section, 127

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we will find an even better way of doing this. 128

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But with what we know, at this point, 129

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this is the best that we can do. 130

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So we take the first bill, 131

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calculate the tip based on that 132

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and put it in position number zero, 133

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then we take bills at position number one 134

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calculate the tip and put it in position one 135

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of this new array, 136

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and then we take bills at position number two, 137

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calculate the tip 138

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and put it at position two of the new array. 139

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And so then, now we end up with this. 140

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Lastly, let's also complete the bonus question 141

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number four here. 142

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And all you have to do here is to create an array, 143

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which will have the sum of the bills and the tips. 144

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So that's gonna be totals. 145

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And now you might have tried to do something like this. 146

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So like bills plus tips. 147

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But as I told you in the previous lecture, 148

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this is simply not gonna work. 149

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So we cannot do any operations on arrays like this, 150

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it doesn't work like that. 151

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So let me show you the result that we would get 152

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from doing this. 153

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And so basically, each of the arrays would be transformed 154

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to a string, and then the two strings would be concatenated. 155

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So that's completely useless. 156

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And so the only thing that we could do 157

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is to say that we want bills at position zero, 158

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plus the tips at position zero. 159

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And now we do this for all the three values. 160

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So at position one as well. 161

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And then at position two. 162

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And so this fixes this error, because now in each position, 163

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we do actually have a real value, 164

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because this is an actual value. 165

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And so with that, we can then do calculations. 166

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So, yeah, this is correct. Looks correct. Right. 167

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And yeah, so with that, all of the four points are solved. 168

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And so here we conclude this part about arrays