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Now we're on section for lesson three and we're going to talk about numbers, numbers are very basic

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data type in JavaScript, lots of other programming languages, use other data types to represent different

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numbers.

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And we're talking about numbers like zero to infinity and negative numbers to some of the other data

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types in other languages or decimals and floats into thirty two or sixty four.

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These are 32 bit numbers, et cetera.

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And so these are used to represent things like thirty seven or negative nine point twenty five or anything

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else.

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Now, when we start with strings, we can put a number inside of a string and it'll treat it as a string.

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If it is if it can be interpreted as a no, we can use the no method.

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And then turn that string into a number.

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And then it just becomes a number so we can turn anything into a number if it if it'll work and numbers

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can be written as decimal binary octal or hexadecimal, very different ways, and these represent different

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bases, if you want to understand what that means.

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As far as numbers go, binary is based to some numbers that are only zero or one.

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Octal is base eight, and that's related to hexadecimal, which is base 16 and notice those are multiple

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powers of two.

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So two times two is four.

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Four times two is eight.

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Eight times two is sixteen.

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Hexadecimal is actually used a lot in programming.

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It's the basis for how we use a lot of our characters and special characters in language.

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So when you type a character in on the computer or an emoji or something, those usually have a hexadecimal

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reference that is interpreted by the computer as something that's part of a kind of this common lexicon

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that computers use called Unicode.

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So let's take a look at that and a little bit more about numbers in code.

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OK, so we're here less than three.

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Let's clear this out.

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So numbers look like this.

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That's a no,

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this is a number right here,

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we could do some math and we could get a resulting number.

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OK.

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So let's go ahead and see what that council does when we look at the three.

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It does three point three, three three repeating and five, interestingly enough, JavaScript can do

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some weird things at lowest digits, at four digits, and they'll be some interesting rounding happening.

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And that has to do with the behavior of float's and to basically it's treating portions of the number

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as fractions.

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And as a result, it you can get some weird behavior, very, very tiny numbers in JavaScript.

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OK, but these are various numbers, if we wanted to have a string, we could have a string like this.

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OK, let's just say a string of five and that's going to be interpreted as a string.

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Now, if we want to print that out.

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Take a look at what that looks like.

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As you can see, it doesn't treat it the same way, it treats it as a string.

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But if we change this to a number first and then print it out, that turns it into a number.

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If we turn it into a number and then print it out, it is interpreted now as a no.

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OK, all right.

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So now if you wanted to turn this back into a string, you could and there are a few.

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The simple way to do that is to go straight.

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String equals string.

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That turns it back into history, another way that you can turn this into a no

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is by doing pass int.

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So you could just do pass it and what that's going to do is it's going to actually look for the numbers

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at the beginning of the street and turn that into a number.

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Cevdet.

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Now, that's a no, and if we started with five, five, six, seven, five, two.

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This would interpret this as five, five, six, seven as the number it's going to find the number at

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the beginning and then stop there.

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Interesting, huh?

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Whereas if you try to do this with no, it would say, hey, that whole thing's not a no.

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That's not a no and OK, you can learn a little bit more about numbers on the Amdocs who have the resources

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in the project, and we'll see you in the next video.