What is JavaScript? | JavaScript Tutorial for Beginners | JavaScript Training | Edureka Rewind

Key Takeaways

JavaScript is arguably one of the most important languages today so the rise of the web has taken JavaScript places it was never conceived to be and we need to take a look at the evolution of this scripting language hi everyone this is shanton from edua and in today's session we will talk about what is Javascript and how it has become one of the most important languages of today and tomorrow now before we begin the session let's have a look at today's agenda so first we will see the origin of JavaScript or how it has actually emerged and next up we will discuss what is Javascript and know a little more about the language moving on we will see that what can JavaScript do and we will have a look at the different Frameworks of JavaScript as well next up we will discuss about the differences between HTML CSS and JavaScript and finally we will have a look at the different benefits of this particular language and finally I will show you some of the fundamentals of JavaScript now before we begin the session don't forget to subscribe to our Eda YouTube channel to keep yourself updated with more such videos now let's get started now how did this particular language come into existence so let's go back and take a look at the origin of JavaScript now Netscape Communications Corporation had a strong presence in the young web its browser Netscape Communicator was gaining traction as a competitor to the NCSA Mosaic the first popular web browser so Netscape was founded by the very same people that took part in the development of Mosaic during the early 9s and now with money and Independence they had the necessary freedom to seek further ways to expand the web and that is precisely what gave birth to JavaScript so this is exactly when Brent and I the father of JavaScript came into the picture now Ike was contracted by Netscape Communications to develop a scheme for the browser now the web needed something which would be easy to grasp syntactically Dynamic to reduce verocity and speed up development and also powerful now Ike saw a chance to work on something he liked and joined forces now the idea at the time was that Java was not suited for the type of audience that would consume mocha that is the scriptors and matures designers Etc Java was way too big and too enterpris for this particular role so the idea was to make Java available for big professional component writers while mocha would be used for small scripting tasks in other words mocha was meant to be the scripting companion for Java in a way analogous to the relationship between cc++ and Visual Basic on the Windows platform now in the year 1995 Netscape Communications and Sun closed the deal mocha or the live script would be finally renamed as JavaScript and it was presented as a scripting language for small client side tasks in the browser while Java was promoted as a bigger professional tool to develop Rich web components now this first version of JavaScript set in stone many of the traits the language is known for to today in particular its object model and its functional features were already present in the first version so now that you know the history behind JavaScript let's move on and see what is Javascript so JavaScript is basically a highlevel interpreted programming language used to make web pages more interactive so have you ever thought that your website is missing something maybe it's not engaging enough or it's not as creative as you want it to be now JavaScript is that missing piece which can be used to enhance web pages applications Etc to provide a more userfriendly experience now JavaScript is basically the language of the web so it is used to make the web look alive by adding motion to it to be more precise it is a programming language that lets you implement complex and beautiful things or design on web pages so when you notice a web page doing more than just sit there and gawk at you you can bet that the web page is using JavaScript now the first feature is that JavaScript is a scripting language and not Java in fact JavaScript has nothing to do with Java then why is it called JavaScript so when JavaScript was first released it was called mocha it was later renamed to livescript and then to JavaScript when Netscape and Sun did a license agreement also it is is an object-based scripting language which supports polymorphism encapsulation and to some extent inheritance as well also doesn't have to be compiled like Java and C which require a compiler finally JavaScript runs in a browser so you can run it on Google Chrome Internet Explorer Safari Etc JavaScript can execute not only in the browser but also on the server and any device which has a JavaScript engine now currently we have hundreds of programming languages and everyday new languages are being created among these are few powerful languages that bring about big changes in the market and JavaScript is definitely one of them it has always been on the list of popular programming languages now according to the stack Overflow for the sixth year in a row JavaScript has remained the most popular and commonly used programming language now let's move on and see what can JavaScript do so JavaScript is mainly known for creating beautiful web pages and applications and example of this is the Google Maps so if you want to explore a specific map all you have to do is click and drag with the mouse and what sort of language could do that of course it's JavaScript now it can also be used in smart watches for example there is this popular Smartwatch maker called the pebble it has created pebble. JS which is a small JavaScript framework that allows a developer to create an application for the pebble line of watches in JavaScript some of the most popular websites like Google Facebook Netflix Amazon they make use of JavaScript to build their websites and not just that among things like mobile applications digital art web servers and server applications JavaScript is also used to make games a lot of developers are building small scale games and apps using JavaScript so now let's move on and have a look at the different JavaScript Frameworks so one major reason for the popularity of JavaScript is the JavaScript Frameworks now the first one is the angularjs so angularjs is the Google's web development framework which provides a set of modern development and design features for Rapid application development then we have the reactjs which is another top JavaScript framework mainly maintained by Facebook and it's behind the user interface of Facebook and Instagram showing off its efficiency in maintaining such high traffic applications we also have the metor GS which is mainly used for providing backend development so using JavaScript on the back end to save time and build expertise is one of the major ideas behind mature and finally we have the jQuery now this can be used when you want to extend your website and make it more interactive so companies like Google WordPress and IBM rely on jQuery now anyone familiar with JavaScript knows that it has something to do with HTML and CSS but what is the relation between these three so let's have a look at the relationship between HTML CSS and JavaScript now think of HTML as the skeleton of the web it is used for displaying the web on the other hand CSS is like our clothes we put on fashionable clothes to look better similarly the web is quite stylish as well so it uses CSS which stands for cascading style sheets for styling purpose and finally there is Javascript which puts life into a web page just like how kids move around using the skateboard the web also motions with the help of JavaScript so now that you know how important JavaScript is to make your web look alive let's have a look at the different and benefits of this language so now there has to be a reason why so many developers love working on JavaScript first of all it's easy to learn and simple to implement so it is a weak type programming language unlike the strong type programming languages like Java and C++ which have strict rules for coding also it's all about being fast in today's world and since JavaScript is mainly a client side programming language it is very fast because any code can run immediately instead of having to contact the server and wait for an answer not just that it also has Rich set of Frameworks like angularjs reactjs which are used to build web applications and perform different tasks JavaScript also builds interactive websites now we all get attracted to beautifully designed websites and JavaScript is the reason behind such attractive websites and applications also it does not require a compiler because the web interprets JavaScript so all you need is a browser like the Google Chrome or Internet Explorer and you can do all sorts of stuff in the browser and finally JavaScript is platform independent and it is supported by all major browsers like Internet Explorer Google Chrome Modzilla Firefox Safari Etc now that you have quite a good idea about this particular language let's move ahead and cover some of the big basic fundamentals of JavaScript so some of the fundamentals involve the variables constants data types objects arrays functions conditional statements loops and switch case so let's first talk about variables now variable is basically a name given to a memory location which acts as a container for storing data temporarily so they are nothing but reserved memory locations to store values now to declare a variable in JavaScript we use the let keyword so now here I've used the visual studio code and here I have typed the Syntax for variable declaration in JavaScript so you just have to use the let keyword and suppose you want to declare a variable as H you can just write let H and semicolon and then you can provide the particular value for this variable now next up is the constants now constants are fixed values that do not change during execution time now to declare a constant in JavaScript we use the const keyword so here I have another example to declare constant in JavaScript so you just have to use this particular keyword as const and then you provide a constant value to this particular variable so it's very easy to declare a variable and a constant in JavaScript now moving on next up is the data types now you can assign different types of values to a variable such as a number or a string in JavaScript you have two categories of data types so you have the Primitive and the reference so for primitive you have num strings Boolean null undefined and for reference you have objects arrays and functions so first of all let's have a look at the objects now an object is basically a standalone entity with properties and types and it is a lot like an object in real life for example consider a girl whose name is Emily age is 22 and eye color is brown so in this example the object is the girl and her name age and eye color are her properties now objects are variables too but they contain many values so instead of declaring different variables for each property you can declare an object which stores all these properties so to declare an object in JavaScript we use the let keyword and also make sure that you use the curly brackets in such a way that all property value pairs are defined within curly brackets so here you can see that we have used the let keyword and then we have used the object where our object is a girl and don't forget to use the curly braces Here and Now inside the object we have certain properties described now these are the properties that belong to our particular object and finally close it with the curly braces as well so so this is how you declare object in JavaScript now moving on next up is the arrays an array is a data structure that contains a list of elements which store multiple values in a single variable for example if we consider a scenario where you went shopping to buy art supplies the list of items you bought can be put into an array now to declare an array in JavaScript we use the let keyword with square brackets and all the array elements must be enclosed Within them so this is the Syntax for declaring an array in JavaScript we use the let keyword here and then we put the variable with the square bracket now inside the square bracket you can also Define the value for your array now when you don't insert any value it is an undefined array and you can put any number of values inside this now next up is the functions so a function is basically a block of organized reusable code that is used to perform single related action so now let's create a function that calculates the product of two numbers now to declare a function in a JavaScript we use the keyword function so here I've used the keyword function and I want to get the product of two variables A and B so I'll just type product in Brackets a comma B and then I'll just return the value of a into B and this will give me the product of these two particular values now here I have declared a function called Product and I have passed two parameters to this function A and B which are the variables whose product is returned by this particular function now moving on next up we have the conditional statements now for the conditional statements we have the if condition and the elif condition now conditional statement is a set of rules performed if a certain condition is met the if statement is used to execute a block of code only if the condition specified holds true and the else statement is used to execute a block of code if the same condition is false now moving on next up we have the loops now Loops are used to repeat a specific block until some end condition is met so there are three categories of Loops in Java Script like the while loop do while loop and for Loop and finally moving on to the final one we have switch case now the switch statement is used to perform different actions based on different conditions so so how does it actually work so the switch expression gets evaluated once then the value of the expression is compared with the values of each particular case and if there is a match the associated block of quote is executed so these were some of the fundamentals involved in JavaScript now to know more about each one of these in details you can go back and check out our JavaScript tutorial video so this was all about today's session I hope you understood what is Javascript and you got to know about the origin of how this language came into existence so with this you aware about the importance of JavaScript so do let us know about your opinion in the comment section below till then thank you and happy learning that