My-Introduction-To-JavaScript
JavaScript for me is a langauge that has a large syntax and also has a way of writing it.
I realized JavaScript has a very similar datatype to Python which data types also include boolean, strings, null value, undefined, symbol, object.
Now I am getting used to learning JavaScript function like
#Alert, Console.log, confirm, prompt,
What I find amazing using JavaScript is the magic of using the same language with other languages like HTML and CSS.
Example of this is using JavaScript HTML methods: getElementById()
<!DOCTYPE html>
<html>
<body><h2> My name is Adeniye Kehinde</h2><p id="demo">I am a technology enthusiast who loves to code.</p><button type="button" onclick='document.getElementById("demo").innerHTML = "Gotcha!"'>want to know more!</button></body>
</html>
Variables can be declared using:
let
const
(constant, can’t be changed)var
Variables defined with const
behave like let
variables, except they cannot be reassigned:
It took me a while before I could understand the word “ Scope” in JavaScript.
The scope is a policy that manages the accessibility of variables. To simplify this, I will try to declare a variable using const
const word = 'Hello';
console.log(word);
Output: 'Hello'
This variable can be log in the next line after the declaration. But when declared outside the scope the variable becomes inaccessible. e.g
if (true) {
const word = 'Hello';
}
console.log(word); // ReferenceError: message is not defined
console.log (word ) through an error because the if
code block creates a scope for word
variable. And word
variable can be accessed only within this scope. i.e {}.
The blockscope variables includes const
and let
but doesn’t includevar
if (true) {
// "if" block scope
var count = 0;
console.log(count); // 0
}
console.log(count); // 0
Even when second console.log(count)
isn’t within the scope{}, it still displayed it output without throwing an error.
A variable declared inside the global scope is named global variable. Global variables are accessible from any scope.
<script src="myScript.js"></script>// myScript.js
// "global" scope
let counter = 1;
Looking forward to continuing learning JavaScript Fundamentals.