JavaScript (JS) is a high-level, interpreted programming language primarily used for making web pages interactive. It is a multi-paradigm language, supporting event-driven, functional, and object-oriented programming styles.
The easiest way of running javascript is in the browser console, open the browser console and type the code bellow in the console tab.
alert("Hello world")Evaluate variable and print if it corresponds to the text.
let js = 'amazing'
if(js === 'amazing') alert('Javascript is Fun')We can make math operations in the console too, it will work just fine.
40+3+90-11Modern Javascript is considered from ES6 onwards, released in 2015, the older version ES5 is a little different, ES stands for ECMAScript.
| Method | What it does |
|---|---|
| console.log( ) | writes (logs) a message to the console. |
| alert( ) | Displays an alert box with a message and an OK button. |
Hoisting is a JavaScript mechanism where variable and function declarations are moved to the top of their scope (before execution), allowing you to use them before they are defined.
const name = prompt("What is your name?")
alert(`Hi ${name}`)
alert("Hi " + name)- Here we read a variable using prompt and print it to the user.
- We can use template strings with ``` to place varibles inside a string to print a variable or use +.
// single line coment
/*
Multi lines
comment
*/To link a javascript file to a HTML page we can use the tag script with the path to the file
<body>
<script src="script.js"></script>
</body>This example assumes that the script file is in the same folder as the index.html