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In this lecture, 2

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we're gonna talk about solving problems. 3

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Solving problems is one of the most important things 4

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in programming. 5

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So if your goal is to become a great programmer, 6

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you need to learn how to deal with problems effectively. 7

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So in this video, I will show you how to think 8

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as a developer by solving problems, 9

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using a simple four step framework. 10

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And let's use our friend John again. 11

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So, after some time John can code now, 12

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he is almost job ready at this point, 13

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but he still needs to work on his problem solving skills. 14

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And in programming, when we say solving problems 15

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we mean a real problem that needs a real solution. 16

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For example, in an array or GPS coordinates, 17

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find the two closest to points. 18

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And this problem is not straight forward, right? 19

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There are a lot of steps involved in solving this. 20

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And so we need a way to effectively solve problems 21

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like this one, or even way more complex ones. 22

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So problem solving does not mean to fix coding mistakes 23

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or bucks, all right? 24

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Anyway, whenever John encounters a problem 25

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that he needs to solve, 26

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he usually just jumps at the problem without much thinking. 27

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He also implements his solutions in an unstructured way 28

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without much of a logical approach. 29

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This makes him stressed out 30

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when things don't work right away. 31

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Another problem that John has, 32

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is that he is too proud to research 33

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when he doesn't know how to come up with his own solution. 34

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So, all of this is not effective at all, 35

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and makes John waste a lot of time. 36

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Now, the first fix to this is to always stay calm 37

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and slow down and not just jump at a solution 38

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without having a plan. 39

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Also, when solving problems, 40

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you need to be in a mindset 41

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of taking a logical and rational approach, 42

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after all programming is just logic, all right? 43

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Then when you are in the right mindset, 44

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just use my four step framework 45

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to solve the problem at hand. 46

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And the first step of the framework 47

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is to make sure that you 100% understand the problem. 48

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Step back and take a high-level look at the big picture. 49

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And the most important part of the step 50

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is to ask the right questions 51

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in order to get a clear picture of the whole problem. 52

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And the best way of understanding this, 53

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is probably to look at an example together here. 54

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So let's say you are working at some company 55

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on some project, 56

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and then your project manager comes and tells you, 57

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"We need a function that reverses, 58

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"whatever we pass into it." 59

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And that's all you know about the problem, 60

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but do you understand it 100%? 61

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Well, probably not, right? 62

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I know that I don't. 63

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So let's ask the right questions to get there. 64

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First we can ask, 65

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what does whatever actually mean in this context? 66

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So, what should actually be reversed here? 67

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Well, and if we think about it, 68

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it only makes sense to reverse strings, 69

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numbers, and arrays. 70

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Objects don't have a well-defined order, 71

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so we can't reverse them. 72

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We're also not gonna reverse like undefined, 73

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or null or a Boolean, right? 74

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Then after we have that figured out, 75

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we can ask, what should we do if something else 76

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is passed in that is no string, number, or array? 77

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How are we gonna handle that? 78

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It's also relevant to ask, 79

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what exactly should be returned from the function? 80

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For example, should it always be a string, 81

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or should the tie be the same as was passed in? 82

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Well, in this case, probably we should always 83

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just returned the exact same type that was passed in. 84

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Also we can start to ask more solution oriented questions, 85

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like how to recognize whether the argument is a number, 86

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a string, or an array? 87

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Or how to actually it reverse a number, 88

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a string and an array. 89

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So these are just some of the questions 90

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that we can ask here. 91

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I'm sure there are more, 92

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but this should already give us 93

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a way more clear picture of this problem. 94

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Now, right now, at the beginning of your journey, 95

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you were probably not yet know, 96

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what the right questions actually are, but don't worry, 97

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this will come with time and practice I promise. 98

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The next step is probably the most important one, 99

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which is the divide and conquer strategy. 100

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Divide and conquer means to break up the big problem 101

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into as many small problems as possible 102

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because these small problems are then a lot easier to solve. 103

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And this also ties in with the previous step 104

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because by dividing the problem into sub problems, 105

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you also take the big problem apart, 106

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until you understand it exactly. 107

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So based on the previous step, 108

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if we wanted to break down this problem, 109

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we could define a couple of sub problems. 110

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First, we need to check if the argument 111

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is a number, a string, or an array. 112

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And this is in fact, a small sub problem, right? 113

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So now, and just solve this one 114

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in isolation and then move on. 115

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The next sub problem is to implement reversing a number, 116

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then implement reversing a string, 117

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and then implement reversing an array, 118

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so that we are ready to deal 119

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whatever is passed into the function. 120

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Finally, we then also need of course 121

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to return the reversed value. 122

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So these are our sub problems, 123

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and they kind of look like a task list 124

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that we now need to go ahead and implement. 125

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And this is great because it makes our work 126

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so much easier now. 127

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Now, sure, this example is a pretty simple problem, 128

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but this strategy works just as well 129

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for bigger and way more complex problems. 130

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In fact, divide and conquer isn't essential method 131

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of problem solving that is also used a lot 132

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outside of programming. 133

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Anyway, with this, we have actually already covered 134

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the two most important steps of the framework. 135

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But now let's say that we actually do not know 136

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how to implement one of these sub problems. 137

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Well, in that case, we should not be afraid 138

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of doing as much research as we have to. 139

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Now, of course, we should always first try 140

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to implement a sub problem on our own 141

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using our own coding abilities. 142

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But if we're constantly hitting a wall, 143

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and cannot move on, then we should waste no more time 144

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and just find out how it works using Google, 145

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or a questions and answers websites 146

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like Stack Overflow, or the MDN JavaScript documentation. 147

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We will see how to use these in the next lecture 148

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when we're gonna work together on a real problem. 149

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And actually researching is a huge part 150

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of a programmer's job, as you will find out very soon. 151

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So you really should not be ashamed 152

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when you don't know enough to solve a certain problem. 153

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Let's just completely normal. 154

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Now, in this case some questions that we could Google are, 155

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how to check if a value is a number, 156

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or an array, or a string in JavaScript. 157

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Or we could Google how to reverse a number, 158

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or a string, or an array in JavaScript, okay? 159

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And again, we will do this in the next lecture 160

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on a real problem together. 161

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Finally, in case we are trying to solve bigger problems 162

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we should put all the previous steps together 163

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and write some so-called pseudo-code 164

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before writing the actual code. 165

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And pseudo-code is simply an informal description 166

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of the actual code that we're gonna write. 167

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So it's like code for humans to understand not computers. 168

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For our example, the pseudo-code 169

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might look something like this. 170

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So you see we use some structures of a programming language, 171

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but this is clearly not JavaScript, right? 172

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And there are no real rules 173

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on how to write pseudo-code either, 174

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you just write so that you understand it yourself, 175

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or other people on your team. 176

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So in this example, we just start 177

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by naming the function as a reverse, 178

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and then we basically pass in a value. 179

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Then we say, that if the type of the value 180

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is not a string and not a number, 181

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and also not an array, then simply return the value back. 182

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And that's because as we defined previously, 183

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we only want dysfunction to work for strings 184

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or for numbers or for a race. 185

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And again, you can clearly see 186

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that this is not any valid JavaScript at all. 187

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But anyway, if the type of the value past this initial test, 188

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then we say if the value is a string, 189

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then reverse the string. 190

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If the value is a number, then reverse the number. 191

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And if the value is an array, 192

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then simply reversed the array. 193

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And then at the end, 194

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we want to return to reversed value, okay? 195

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So this is really more like a list of instructions 196

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that we now could go ahead and actually implement 197

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using the JavaScript language. 198

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Okay, and that's it. 199

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That's the four steps to solve any problem 200

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no matter how big. 201

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And now before I leave you, a final tip I can give you, 202

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is to develop a genuine curiosity and passion 203

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for understanding how things actually work, 204

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not only in programming, 205

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but really in the whole world around you. 206

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For example, the famous scientist Richard Feynman, 207

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was repairing radios when he was just a teenager, 208

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and Elon Musk made his first computer game when he was 12. 209

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And there are many more examples like this, 210

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and all of them became geniuses in their fields 211

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in part because of their genuine curiosity 212

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on how the world around them works. 213

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All right, and with that being said, 214

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let's now go ahead and solve a real problem 215

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in the next lecture using this framework 216

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that we just learned about. 217

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So I'll see you there.