JavaScript
is a scripting language which makes the webpages more interactive.
Like,
adding a calculator or a quiz in the webpage, JavaScript is needed.
We require notepad ++ for writing JavaScript commands.
<Script> </Script> tags should be added so that the browser will
know which scripting language we are using.
Example:
<Script type = “javascript”> </Script>
A variable is nothing but a placeholder.
X = Chocolate
Kids love X.
X is made from Cocoa.
Similarly, in JavaScript, the variable is represented as
‘var’.
var x = 25;
document.write(x);
Result: 25
Different types of variables:
The numbers can be
stored by declaring “var”.
The words can be stored by adding quotation marks “apple”
When you add words like:
var fruit = “Amanda said, “I like oranges””;
Result: <empty page>
We need to add escape characters so that it gets printed:
var fruit = “Amanda said, \“I like oranges\” ”;
Result: Amanda said, “I like oranges”.
We can use escape character if we need to escape something
from the result.
In order to use variables and strings together, mention it
with “+”.
var fruit = “Orange”;
var color = “Black”;
document.write(fruit + “is my favorite” );
Result: Orange is my favorite
Functions:
The function is defined with the function keyword.
You can use a function declaration and get real values when invoked.
function fruit()
{
alert(“Berry!”);
}
fruit();
In order to use function in HTML:
<form>
<input type =”button” value=”pineapple”
onclick=”fruit()”>
</form>
Passing values into function
function fruit(x){
alert(“I love”+x);
}
fruit(“Apple”);
fruit(“Banana”);
fruit(“Cranberry”);
Passing multiple parameters in function:
function fruit(one, two){
document.write(one + “ is better than “+ two + “<br/>”);
}
fruit(“Cranberry”,”Blueberry”);
fruit(“Dog”,”Cat”);
fruit(“Rose”,”Jasmine”);
Result: Cranberry is
better than Blueberry
Dog is
better than Cat
Rose is better than Jasmine
Return statement:
Return is to return the value passed by parameters in a
function.
function addNumbers(a, b){
var c = a+b;
return c;
}
document.write(addNumbers(3,2));
Result: 5
Reference: https://thenewboston.com
