Tuesday, May 30, 2023

JavaScript Operators

Types of JavaScript Operators

There are different types of JavaScript operators:

Arithmetic Operators
Assignment Operators
Comparison Operators
String Operators
Logical Operators
Bitwise Operators
Ternary Operators
Type Operators
Operator Description
+ Addition
- Subtraction
* Multiplication
** Exponentiation (ES2016)
/ Division
% Modulus (Division Remainder)
++ Increment
-- Decrement

Operator	Description
+	Addition
-	Subtraction
*	Multiplication
**	Exponentiation (ES2016)
/	Division
%	Modulus (Division Remainder)
++	Increment
--	Decrement

Example
<!DOCTYPE html>
<html>
<body>

<h1>JavaScript Arithmetic</h1>
<h2>The += Operator</h2>

<p id="demo"></p>

<script>
var x = 10;
x += 5;
document.getElementById("demo").innerHTML = x;
</script>

</body>
</html>

Saturday, May 20, 2023

JavaScript Functions

JavaScript Function Syntax

A JavaScript function is defined with the function keyword, followed by a name, followed by parentheses ().

Function names can contain letters, digits, underscores, and dollar signs (same rules as variables).

The parentheses may include parameter names separated by commas:
(parameter1, parameter2, ...)

The code to be executed, by the function, is placed inside curly brackets: {}

function name(parameter1, parameter2, parameter3) {
// code to be executed
}

<!DOCTYPE html>

<html>

<body>

<h1>JavaScript Functions</h1>

<p>Call a function which performs a calculation and returns the result:</p>

function myFunction(p1, p2) {

return p1 * p2;

}

let result = myFunction(4, 3);

document.getElementById("demo").innerHTML = result;

</script>

</body>

</html>

JavaScript Variables

4 Ways to Declare a JavaScript Variable:

Using var
Using let
Using const
Using nothing
What are Variables?
Variables are containers for storing data (storing data values).
In this example, x, y, and z, are variables, declared with the var keyword:
Redeclaring a Variable Using let
Redeclaring a variable inside a block will not redeclare the variable outside the block:
Redeclaring a variable using the let keyword can solve this problem.
When to use JavaScript const?
Always declare a variable with const when you know that the value should not be changed.
Use const when you declare:
- A new Array
- A new Object
- A new Function
- A new RegExp
  Constant Objects and Arrays
  The keyword const is a little misleading.
  It does not define a constant value. It defines a constant reference to a value.
  Because of this you can NOT:
  - Reassign a constant value
  - Reassign a constant array
  - Reassign a constant object
  - Change the elements of constant array
  - Change the properties of constant object
  Constant Arrays
  You can change the elements of a constant array:

Monday, May 15, 2023

JavaScript Output

JavaScript Display Possibilities

JavaScript can "display" data in different ways:

Writing into an HTML element, using innerHTML.
Writing into the HTML output using document.write().
Writing into an alert box, using window.alert().
Writing into the browser console, using console.log().
Using innerHTML
To access an HTML element, JavaScript can use the document.getElementById(id) method.
The id attribute defines the HTML element. The innerHTML property defines the HTML content:
<!DOCTYPE html>
<html>
<body>

<h2>My First Web Page</h2>
<p>My First Paragraph.</p>

<p id="demo"></p>

<script>
document.getElementById("demo").innerHTML = 5 + 6;
</script>

</body>
</html>
Using document.write()
For testing purposes, it is convenient to use document.write():
<!DOCTYPE html>
<html>
<body>

<h2>My First Web Page</h2>
<p>My first paragraph.</p>

<p>Never call document.write after the document has finished loading.
It will overwrite the whole document.</p>

<script>
document.write(5 + 6);
</script>

</body>
</html>
Using window.alert()
You can use an alert box to display data:
<!DOCTYPE html>
<html>
<body>

<h2>My First Web Page</h2>
<p>My first paragraph.</p>

<script>
window.alert(5 + 6);
</script>

</body>
</html>

Friday, May 12, 2023

External JavaScript

External JavaScript Advantages

Placing scripts in external files has some advantages:

It separates HTML and code
It makes HTML and JavaScript easier to read and maintain
Cached JavaScript files can speed up page loads

To add several script files to one page - use several script tags:

<!DOCTYPE html>

<html>

<body>

<h2>Demo External JavaScript</h2>

<p id="demo">A Paragraph.</p>

<p>This example links to "myScript.js".</p>

<p>(myFunction is stored in "myScript.js")</p>

</body>

</html>

Monday, May 8, 2023

JavaScript Tutorial

Why Study JavaScript?

JavaScript is one of the 3 languages all web developers must learn:

1. HTML to define the content of web pages

2. CSS to specify the layout of web pages

3. JavaScript to program the behavior of web pages

Web Design& development programming Studio

Pages

Tuesday, May 30, 2023

JavaScript Operators

JavaScript Operators

Types of JavaScript Operators

Example
<!DOCTYPE html>
<html>
<body>

<h1>JavaScript Arithmetic</h1>
<h2>The += Operator</h2>

<p id="demo"></p>

<script>
var x = 10;
x += 5;
document.getElementById("demo").innerHTML = x;
</script>

</body>
</html>

Saturday, May 20, 2023

JavaScript Functions

JavaScript Function Syntax

JavaScript Variables

JavaScript Variables

4 Ways to Declare a JavaScript Variable:

What are Variables?

Redeclaring a Variable Using let

Redeclaring a variable using the `let` keyword can solve this problem.

When to use JavaScript const?

Constant Objects and Arrays

Constant Arrays

Monday, May 15, 2023

JavaScript Output

JavaScript Display Possibilities

Using innerHTML

Using document.write()

Using window.alert()

Friday, May 12, 2023

External JavaScript

External JavaScript Advantages

Monday, May 8, 2023

JavaScript Tutorial

Why Study JavaScript?

JavaScript Animated

Report Abuse

Labels

Pages

Tuesday, May 30, 2023

JavaScript Operators

Types of JavaScript Operators

Example<!DOCTYPE html><html><body><h1>JavaScript Arithmetic</h1><h2>The += Operator</h2><p id="demo"></p><script>var x = 10;x += 5;document.getElementById("demo").innerHTML = x;</script></body></html>

Saturday, May 20, 2023

JavaScript Function Syntax

JavaScript Variables

4 Ways to Declare a JavaScript Variable:

What are Variables?

Redeclaring a Variable Using let

Redeclaring a variable using the let keyword can solve this problem.

When to use JavaScript const?

Constant Objects and Arrays

Constant Arrays

Monday, May 15, 2023

JavaScript Display Possibilities

Using innerHTML

Using document.write()

Using window.alert()

Friday, May 12, 2023

External JavaScript Advantages

Monday, May 8, 2023

Why Study JavaScript?

Example
<!DOCTYPE html>
<html>
<body>

<h1>JavaScript Arithmetic</h1>
<h2>The += Operator</h2>

<p id="demo"></p>

<script>
var x = 10;
x += 5;
document.getElementById("demo").innerHTML = x;
</script>

</body>
</html>

Redeclaring a variable using the `let` keyword can solve this problem.