JavaScript from Beginner to Advanced Part 5 [w/ subs]



00:00:01 – you may have noticed before that I use
00:00:04 – the + operator for like adding for when
00:00:07 – we assign two variables multiple values
00:00:09 – to the + operator if you remember that
00:00:10 – well in this section will be actually
00:00:13 – mentioning some of the actually all the
00:00:16 – kinds of operators we have in JavaScript
00:00:18 – an operator's allow operations to occur
00:00:21 – so operations are raised with any sort
00:00:23 – of mathematical any sort of like any
00:00:27 – sort of work done with data values so
00:00:31 – basically we'll be dealing with numbers
00:00:33 – in this in this in this tutorial so
00:00:36 – working with all the operations we have
00:00:37 – excuse me we have what numbers we have
00:00:41 – five types of i divided them into five
00:00:44 – subgroups of operators we have
00:00:46 – arithmetic we have assignment we have
00:00:49 – bitwise comparison and logical and we're
00:00:52 – going to have a look at all of them so
00:00:53 – the first one we have is arithmetic it
00:00:55 – has the fault we use the following
00:00:56 – symbols for those you falling operator
00:00:59 – so we have plus minus multiplication
00:01:03 – division and yet the basic and modulo
00:01:08 – where there's modulo module here we go
00:01:11 – and there we go so that's those are our
00:01:14 – basic mathematical operators we also
00:01:17 – have exponential which actually doesn't
00:01:20 – work I'll talk about that in a bit so
00:01:22 – let's just go each one one by one so far
00:01:25 – a we're going to call have some
00:01:26 – variables now our B equals seven
00:01:29 – d'ivoire c equals so this is addition
00:01:32 – just simply eight adding two numbers
00:01:35 – together console see pretty simple stuff
00:01:41 – with math pretty straightforward
00:01:42 – mathematical stuff so 12 subtraction you
00:01:47 – just do minus denoted with the dash
00:01:50 – operators are denoted with this pink
00:01:52 – like this this is also an operator the
00:01:55 – assignment operator is like one of the
00:01:58 – main assignment operator so it means the
00:01:59 – left side is going to be set equal to
00:02:01 – the right side and minus is a binary
00:02:05 – operator which means it takes two
00:02:07 – operands so because a and B left and
00:02:10 – right operand left right if you those
00:02:13 – are called binary
00:02:15 – binary on sand to we won't actually say
00:02:18 – that southern binary will confuse it
00:02:19 – with bitwise which was in binary numbers
00:02:21 – anyway sorry about that what I'm saying
00:02:23 – is the left and side and right side are
00:02:26 – called operands this is an operand and
00:02:28 – this is an operand and that's the
00:02:29 – operator alright so that was subtraction
00:02:32 – multiplication multiplying them 35 5
00:02:36 – times 7 35 division it'll is so like in
00:02:41 – JavaScript like I said numbers are one
00:02:42 – type so it will turn the exact value
00:02:44 – significant to like 10 I don't know how
00:02:48 – many dishes here 13 digits i think i
00:02:50 – will see that in a later chapter and on
00:02:53 – time to count them right now on ok so
00:02:55 – let's see and then we have modulo you're
00:02:58 – not familiar with modulo that is
00:02:59 – basically divide the numbers together
00:03:02 – and you get the remainder so when you
00:03:04 – divide it you get 5 so 5 divided by 7
00:03:07 – results in some sort of value get 5
00:03:10 – afterwards now if that if that result
00:03:14 – was kind of weird-looking let me do
00:03:16 – something simpler that we use modulo 4
00:03:18 – so i use module oftentimes when we want
00:03:21 – one I want to get check and even odd
00:03:23 – numbers so here's 44 even number when
00:03:26 – you divide it by 2 you're checking so
00:03:28 – when you modulo 2 gets remainder 40 so
00:03:32 – you get 44 / to get better remainder
00:03:35 – which is 0 because it's a clean division
00:03:37 – that means it's an even number so when
00:03:40 – this results when a modulo of the left
00:03:43 – love modular right equals 0 that means
00:03:46 – the left side is an even number so a is
00:03:50 – an even number which is 44 that's an
00:03:52 – even number so 43 if we do that there
00:03:55 – that means we get one because if there's
00:03:57 – a remainder 1 that means it's an odd
00:03:59 – number when you modulo 2 so 4 T 3 modulo
00:04:02 – 2 is one which means 43 is an odd number
00:04:05 – you can also use when checking if an
00:04:07 – unknown value being any budget is an odd
00:04:09 – number or you a number which will see
00:04:11 – you when we talk more about conditional
00:04:13 – statements but anyway let's move on so
00:04:17 – the last arithmetic operator is this
00:04:19 – star star in this current um there's
00:04:23 – select sort of versions and types of
00:04:26 – JavaScript out there on the internet
00:04:28 – in certain browsers they certain types
00:04:30 – of script syntax or JavaScript are used
00:04:33 – in mine this operator doesn't work I
00:04:38 – tested it before this video in like
00:04:40 – sorry three schools it will talk about
00:04:43 – it for example and say it works on
00:04:45 – sitting a lot of cases by some cases it
00:04:47 – doesn't all my case it doesn't so I
00:04:49 – can't really demonstrate here but this
00:04:51 – will basically example throat up here 25
00:04:54 – this should return 32 and some browsers
00:04:57 – and some interpreters of JavaScript but
00:05:01 – some in my case it doesn't work anyway
00:05:03 – moving on let's get to the some other
00:05:07 – over the choppers we have we have a
00:05:09 – couple more actually they're incremental
00:05:11 – operators you have plus plus and minus
00:05:13 – minus so what these are they allow you
00:05:17 – to increment and decrement operators
00:05:19 – these are often used in when you're
00:05:22 – working with iterations such as in loops
00:05:23 – so let's take a look at the following so
00:05:28 – we're going to need one variable for
00:05:29 – this let's return out the 434 so we have
00:05:33 – plus plus what this does you see it
00:05:38 – didn't it's supposed to increment the
00:05:40 – value by a 1 plus plus so that's a plus
00:05:43 – plus does well if as you can see here it
00:05:47 – didn't do for you didn't just play 45 as
00:05:51 – it should but this one will display 45
00:05:54 – what this is is this is prefix meaning
00:05:59 – that it'll increase the value first and
00:06:01 – then work with it and somewhat in some
00:06:03 – way if you do after it'll return the
00:06:06 – current event the original value and
00:06:08 – then increase it or the current value
00:06:10 – and then increase it afterwards so let
00:06:12 – me do this this is a kind of thing and
00:06:17 – programming it should be understood see
00:06:21 – we'll see what happened here i increased
00:06:23 – it twice basically so i should actually
00:06:25 – remove that so like i said ok give me a
00:06:29 – the first time 44 increase it and then
00:06:33 – said give me whatever value eight is
00:06:35 – increased immediately that's what this
00:06:36 – brief this is called prefix and this is
00:06:39 – called post fix
00:06:41 – so let me remove this C and the next
00:06:45 – time you get 45 that's because we we
00:06:48 – took it increased it afterwards after
00:06:51 – getting it taking it and working with it
00:06:53 – then its values 45 the same thing goes
00:06:56 – for minus so we said a can be 44 then
00:07:00 – subtract it and then return the value
00:07:03 – again some 43 and then prefix so
00:07:07 – probably a postfix and prefix so 4343
00:07:13 – yeah so that's prefix and postfix of
00:07:16 – these increment operators are also
00:07:18 – considered arithmetic because you're
00:07:19 – essentially adding one to them so it's
00:07:22 – like saying a plus equals one and that
00:07:25 – leads us to our next set of operators
00:07:27 – which are assignment operators they're
00:07:29 – pretty simple it's just basically these
00:07:32 – arithmetic operators and adding equal
00:07:35 – sign so this was the additional addition
00:07:39 – assignment which is basically saying a
00:07:41 – equals 44 then a plus 1 and then saying
00:07:47 – give me back a this is also Plus Ones
00:07:53 – also equivalent to equal sign so notice
00:07:57 – here it didn't do anything because that
00:08:01 – only works on that line itself but if we
00:08:04 – wanted actually so what we did here this
00:08:06 – is some sort of floating global value
00:08:08 – global values will talk about scope so
00:08:11 – we're saying here a +1 at this line is
00:08:14 – going to be 40 44 45 and then you notice
00:08:19 – here it's not stored to anything that's
00:08:21 – because we didn't assign this operation
00:08:24 – to the value so we have to assign an ad
00:08:27 – so we're adding so we're saying okay
00:08:30 – aids new value is going to be a plus 1
00:08:33 – this is equivalent to this actually a
00:08:35 – plus 1 45 instead of duplicating the
00:08:40 – writing of a you just do that so that's
00:08:44 – assignment operator and you do the same
00:08:46 – thing with all the others so minus 1 for
00:08:49 – example you can actually change the
00:08:52 – number up the same
00:08:53 – is two freshmen to that right and save
00:08:58 – it okay to you can do / 2 22 you can
00:09:05 – multiply by 2 multiplied in sign so
00:09:10 – basically so you don't have to say plus
00:09:12 – then equal a equals april's to for
00:09:15 – example because if you just do a plus 2
00:09:17 – by itself it won't save and you can also
00:09:20 – do módulo as well and you get 0 so
00:09:24 – basically you're saying okay give me a
00:09:25 – then sign it assign the value we're
00:09:29 – equal to this operator done with this
00:09:31 – number all right if that sounds if
00:09:34 – that's okay alright so moving on if you
00:09:37 – for following this list now we have now
00:09:41 – bitwise operators so bitwise operators
00:09:45 – basically work with allow us to work
00:09:47 – with binary values values for now
00:09:49 – familiar binary numbers you might not
00:09:52 – get these so i recommend you before
00:09:54 – diving into this you might want to
00:09:56 – revert refreshing binary numbers level
00:09:59 – but i will try my best to show you what
00:10:01 – everything is doing so let's say we have
00:10:03 – a bar called bin one big one we're going
00:10:07 – to say seven and to actually let me let
00:10:14 – me actually write out the binary
00:10:16 – operators to bitwise operators so we
00:10:17 – have and we have or we have inverse
00:10:24 – where's inverse of squiggly for what
00:10:27 – it's called we have left shift we have
00:10:29 – right shift and I believe I believe
00:10:34 – that's it yes and we have we're supposed
00:10:36 – to have nope that is I believe that is
00:10:42 – it no we also have one more which I
00:10:45 – forgot is I think X or it looks like
00:10:48 – that will explain all of don't worry so
00:10:51 – here we have seven and two so notice
00:10:57 – here how I didn't write binary numbers
00:10:59 – that's because in JavaScript when you
00:11:02 – see right the operator this one the left
00:11:04 – and right sides of it will be
00:11:05 – automatically
00:11:06 – considered a binary so these numbers
00:11:10 – would like this in binaries just so you
00:11:12 – don't have to reference anything so this
00:11:15 – should be like 0 1 1 1 and 0 0 1 0 which
00:11:21 – equals 0 0 1 0 when you have been one
00:11:28 – you'll see that the result is to which
00:11:32 – goes in binary so this would be 1 1 is 2
00:11:35 – this is 2 yep checks out let's do or now
00:11:38 – or of these two loops or oh these two so
00:11:42 – it look like this poor would be the
00:11:45 – following it would actually be 0 1 1 1
00:11:49 – that number is 7 so we or operator which
00:11:54 – checks basically if if you see a 1
00:11:58 – combination of 10 or 11 you will get one
00:12:03 – as a result and by the way I should have
00:12:06 – explained and means if you only have the
00:12:09 – result 11 comparing to each bit that
00:12:13 – means they get a 1 so that's why it is
00:12:15 – only with this one of those one so
00:12:18 – that's and and now we have I should say
00:12:21 – X or first X or that means we'll have a
00:12:26 – case where only their want different
00:12:29 – values so only when we have zero one
00:12:34 – soul of comparing the first 10
00:12:37 – Carnesecca 11 comparing the third 10
00:12:40 – wearing the second one and you'll see
00:12:44 – the result oops I didn't change that X
00:12:50 – sores will shift six that's five that
00:12:53 – checks out yep that's five and next we
00:12:57 – have inverse so inverse is basically
00:13:02 – inverts the bits let's do that with one
00:13:06 – number actually there we go so that's
00:13:11 – basically not if you're familiar not in
00:13:16 – binary just basically shift so
00:13:19 – you say not 0 1 0 1 equals 1000 this is
00:13:24 – unsigned by the way so you actually know
00:13:27 – it is signed a while it is signed so um
00:13:29 – you get minus 8 from that so that's not
00:13:33 – you can actually even do this with
00:13:35 – multiple inverses so let's say and kind
00:13:39 – of like that and five so you can even do
00:13:44 – this that's basically and you'll get the
00:13:48 – following so you can basically make some
00:13:51 – match operators the same thing goes for
00:13:53 – an arithmetic which we'll get into a
00:13:55 – great deal detailed more examples as we
00:13:57 – progress through these this course
00:13:59 – alright so that's bitwise operators wait
00:14:03 – there's a couple more there's oh there's
00:14:04 – left shift and there's right shift so
00:14:07 – these two right here left shift right
00:14:09 – shift so let's say we have the number 20
00:14:13 – and we're going to say left this one too
00:14:17 – so what this says is anyone's are
00:14:20 – shifted off the number are removed
00:14:23 – actually wait no left shift what it does
00:14:26 – it shifts bits in the number of whatever
00:14:29 – place is defined here so we're saying
00:14:32 – shift the bits same here let's so you
00:14:37 – have 0 1 0 1 0 0 that's that is 20
00:14:43 – shifted to the left to buy two bits
00:14:46 – basically translates to 10 100 and any
00:14:52 – bits that are shifted off the edge here
00:14:56 – are deleted for good so let's do that
00:14:59 – you get 80 so this will check out to be
00:15:03 – 80 let me see ya so when you shift the
00:15:09 – binary result of 20 by two to the left
00:15:12 – so increasing the number you'll get 80
00:15:14 – and if you do it to the right so let's
00:15:18 – do that by one instead and you'll get 40
00:15:21 – so let's do it by left by one I mean
00:15:26 – right by one give the bits to the right
00:15:28 – now so going that way pointing to the
00:15:31 – where this goes you should
00:15:32 – j'adore right by one and that's going to
00:15:35 – be basically so shift to the right by
00:15:39 – one to Morgan to see more visual equals
00:15:41 – 0 0 1 0 0 1 0 and that's going to be 10
00:15:48 – yep so you got to and you got weights 0
00:15:54 – 0 1 0 1 2 2.1 248 actually this should
00:16:03 – be shifted to hear there you go that's
00:16:05 – 10 that's correct alright so moving on
00:16:09 – we have comparison operators now besides
00:16:12 – maybe a little boring you but I'll try
00:16:13 – to pick up the pace a little so
00:16:15 – comparison operators are basically they
00:16:17 – return boolean values so return true or
00:16:20 – false based on what we have so basically
00:16:22 – they're like in comparison mathematics
00:16:25 – so you have left greater than less than
00:16:27 – you have equal signs equal sign and
00:16:30 – comparisons is always 2 equals because
00:16:32 – the signal equals is the assignment
00:16:34 – operator yourself left set greater than
00:16:36 – or less than greater than or equal to or
00:16:39 – less than or equal to and you know and
00:16:42 – you have a course the last 13 which I
00:16:44 – mentioned one last tutorial this
00:16:46 – basically checks for the type the equal
00:16:49 – value and the type which will see right
00:16:51 – now so let's say we have far i equals 77
00:16:56 – to the car B equals actually equals 66
00:17:03 – just a console right say a so equals B
00:17:07 – that's going to be false we're going to
00:17:09 – say is less than B also false 77th
00:17:14 – greater than 60 60 k is greater than B
00:17:16 – true and we're going to say now less
00:17:22 – than or equal to greater than equal to
00:17:25 – sorry and then we say less than or equal
00:17:27 – to which is false see all these
00:17:29 – operators return false and now let's do
00:17:31 – equals equals so okay that's fault
00:17:35 – obviously but let's do so let's say B is
00:17:39 – actually 77 in a string if we City equal
00:17:42 – with a point to that's true because when
00:17:46 – convert this to a number they're
00:17:48 – essentially they represent the same
00:17:50 – value the data so Java scripts like oh
00:17:52 – yeah that's easy they're both 77 duh but
00:17:56 – what if we don't want that we want to
00:17:57 – check if the input strictly number 77
00:18:00 – and not the strings already said well
00:18:02 – you use the 33 equal signs of the triple
00:18:05 – equal sign operator I forgot to call
00:18:08 – it's like the checks the type the type
00:18:10 – the type and value so this is all the
00:18:15 – news when you're checking input and you
00:18:16 – want to make sure something's a string
00:18:18 – or integer for example or you're
00:18:21 – verifying input and you'll see you'll
00:18:23 – see this a lot more when we compare
00:18:24 – operators alright moving on let's
00:18:29 – finally do the next I think that's all
00:18:32 – of the code you also have not this
00:18:41 – basically converts the boolean result of
00:18:43 – this so like not and we have not I think
00:18:49 – that's the next one oh yeah that's the
00:18:51 – next one actually so we hope this helped
00:18:54 – and we hope to see you next time


Video Url:
http://youtu.be/sYpeS1SUKKw

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