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Hey, everyone.

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Welcome back.

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Continuing with the data types, we're now going to talk more about numbers before we get started.

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I just want to say something quickly.

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I'm just using the console to write the examples just so it's faster, just so I don't have to go back

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and forth to Visual Studio Code and then back here.

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But I encourage you to write all the examples inside the JSC file.

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So you have everything there.

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Of course, any time you want, you can come back here to the written material and check all the examples

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again.

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This is why I made this material.

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So having said that, let's move on.

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We know that we can assign numbers to variables.

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All we need to do is use only numbers and don't use quotation marks.

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So if we include quotation marks, JavaScript is going to treat this as a string.

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So like this, JavaScript knows we are working with a number.

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So we have integers.

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And we also have numbers with decimal places like this.

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We should always use DOT.

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So never use comma.

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And we also cannot use thousand separators.

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So if I have a price variable.

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So var price, let's say the price is more than a thousand.

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I can't do it like this.

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This is going to confuse JavaScript.

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And this is going to return an error.

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We never use thousand separator.

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So this is a thousand.

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This is ten thousand.

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This is how we write numbers.

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And if you have decimal places you should use DOT.

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So this is the right way of writing a number.

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We also have big numbers in JavaScript so we can represent them with this exponential notation.

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So we don't have a very, very long number.

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This number here means two times 10.

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By the power of 45.

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So now let's check some calculations that we can do with numbers.

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So, of course, we have the basic math operations when dealing with programs.

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We're going to do calculations all the time.

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So we need at least the basic math calculations.

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So I can have a variable.

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Called Numb one.

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Actually, I just added an empty space here.

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So now it's right, so numb.

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One.

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I'm also going to create another variable num, too.

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And now we can make any kind of calculations we want.

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So some is just going to be number one plus.

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Numb, too, as you can see, we have the calculation done here.

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We can also do subtraction.

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We have a dash division.

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We have a forward slash and multiplication with an asterisk.

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Just one thing that you might be asking yourself.

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Why was I using console dot log in the code?

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And now I'm not doing this anymore.

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I'm just typing in the operations directly.

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If you're in the console here, you can just type it directly like this.

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But this is not going to work in the JavaScript file.

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In the JavaScript file.

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If you want to send anything to the console, you need to write, console, dot log.

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So moving on, we can also use parentheses to form expressions.

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So if we want the average of these two numbers, you should just write it like this.

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So num one plus.

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Numb, too, divided by two.

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This is not going to be correct because following the hierarchy of math operations, it is going to

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do the division first and then it's going to do the some.

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So in order to sum the numbers first, we just enclose them inside parentheses like this.

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And then we do the division.

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So now we have the correct average.

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Let me clear this real quick.

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And now let's talk about the math object, if we want to go further with calculations, maybe we want

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more than just the basic math operations.

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We have a built in object in JavaScript.

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It is called math.

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We have a capital M so we can use it to make some more complex stuff like two to the power of four.

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So how can we do this?

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We can just type math and then any method of the math object can be access.

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We have a dot when you do this.

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You have all the lists.

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So the console brings all the list of methods that we can use with the math object.

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So if we type Powell.

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So now two to the power of four is just two karma, four to now we have the result, which is 16.

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We can also round numbers so we can use the round method.

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And this is going to just round to the nearest integer so I can do math.

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That round.

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And then if I'm trying to round two point seven, it is going to round two three.

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If I'm trying to round two point three, it is going to round two to.

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We can also round two, the current integer, so math dot floor.

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It doesn't matter if I have nine here.

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It is always going to round to the low integer and the opposite would be the CEO.

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Method.

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So this time it is going to round to the bigger integer.

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So even if I have to point to, it's still going to round two, three.

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Sometimes it's useful to do this.

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Now we also have the square root.

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And another very interesting thing we have with the math object.

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We programmers use this a lot.

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Is the random method.

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So if you do it like this, we always need parentheses for methods.

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We're going to talk more about this even if we don't pass anything inside.

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We should always use parentheses to run methods.

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So now we are calling the random method.

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And what it does is generating a completely random number between zero and one.

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So if I do this one time, it comes one number.

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If I do this another time.

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Now it's a different number.

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Every time we do it, it's going to be a completely different number.

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So now how can we have a random number between zero and 100?

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For example.

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Wow, it's easy.

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We can just do math.

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Dot random.

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Then we multiplied by 100.

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So the smallest one, which is zero, is going to be zero.

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And the biggest one, which would be zero point ninety nine, is going to be close to 100.

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So this way we have a random number from zero to 100.

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And now if we want to around it, we can just use the math that round.

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And now every time we run this, we are going to have a random number from zero to 100.

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Pretty cool right now besides the math object.

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We also have some methods that can be used with the no data type.

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So one example is the two fixed method.

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So wi fi, have a number.

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Let me just clear this real quick.

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I'm going to create a variable called my.

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The number equals.

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Three point something just like this.

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Now, if I use the round function from the math object, it is just going to round it to four.

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I could use the floor or the CEO methods, but still, it's not exactly what I want because maybe I

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just want to round this number to two decimal places.

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So in order to do this, we can call the variable my number.

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So now it's just a different way of writing it.

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So we just use the name of the variable and then a dot and then we can write to fix it, which is the

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name of this method.

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And inside here, we just informed the number of decimal places we want you if we don't write anything

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here is just going to round to no decimal places.

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If we write to, then it's going to round to two decimal places.

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Three, four.

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We can choose anything we want here.

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So at this point, you might be getting a bit confused because with the math object, we just wrote

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it like this.

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So math dot round.

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And then we place the number inside.

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So in this example, we would just write it like this.

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So math dot round.

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And then inside it.

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We are going to put our variable, so my number.

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So we would write it like this.

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And this is a different way of writing it.

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So my suggestion to you is that you don't worry about this at the moment because all of these things

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are going to be learned naturally.

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You don't have to understand everything.

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Why this one?

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You write it like this.

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Why this one?

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You write it like that.

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The intention here is just to get started getting comfortable with JavaScript writing code.

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And then you see that you won't have any trouble understanding these things.

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All right.

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So moving on now.

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We are going to talk about incremental operators, but this video is getting a bit too long.

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So I'm going to stop it here and we're going to continue in the next video.