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Text in HTML

HTML elements are used to describe the structure of the page like

headings paragraphs

Headings and paragraphs

  • Headings HTML has six levels of headings:

used for main headings

used for sub headings

used for sub headings

used for sub headings
used for sub headings
used for sub headings
  • Paragraphs

to create a paragraphs, surround the words with the p element with openning tag <p> and closing tag </p> By default, a browser will show each paragraph on a new line

  • we can use more tags to structured the text and make it easier to read and more visibel to the user like :

bold with the <b> element italic with the <i> element use superscript <sup> element and subscript <sub> element to contain contain characters for example

<p>On the 4<sup>th</sup> of September you will learn
 about E=MC<sup>2</sup>.</p>
<p>The amount of CO<sub>2</sub> in the atmosphere
 grew by 2ppm in 2009<sub>1</sub>.</p>

and there are many element we can use to make the web page easier to read like whie space and line breaks

The Semantic markup is :

a text elements that give information to the page about the content inside the openning tags and the closing tags like the

p element that indicate that the content inside is a paragraph and the browser will know how to show the paragraph ( the text elemets )

*some example of the semantic element:

<strong > <address> <article>

CSS

  • CSS stands for Cascading Style Sheets and its control the design the layout of the web page its allowspecify how the content of an element should appear

  • CSS treats each HTML element as if it appears inside its own box and uses rules to indicate how that element should look

  • CSS works by associating rules with HTML elements, A CSS rule contains two parts: a selector and a declaration for exmaple

p {
 font-family: Arial;}

the p is the selector the font family is the declaration inside curly brackets contain a property font-family and a value Arial

we can use CSS with HTML in three ways :

  1. internal inside the opening tag
  2. external inside the <style> element
  3. external style sheet by linking the HTML file with the CSS file using the <link> element

Javascript

  • a script is a series of f instructions that a computer can follow step by step every step known as a statement

  • Statement are instructions and every statement start on a new line and can be organized into code blocks

  • Statements should end with a semicolon Example

var today= new Date{);
var hourNow = today.getHours{) ;
var greeting;
if (hourNow > 18) {
greeting= 'Good evening';
else if (hourNow > 12) {
greeting= 'Good afternoon';
else if (hourNow > O) {
greeting 'Good morning';
else {
greeting 'Welcome';
document.write(greeting) ;
  • We can use comments to explain what the code does

MULTI-LINE COMM ENTS we start with /* and end with *\ characters SINGLE-LINE COMMENTS we start with // anything that follows the two forward slash characters will not be processed by JavaScript

*JavaScript distinguishes between numbers (0-9), strings (text), and Boolean values (true or false)

what is variables

  • the data stored in a variable can change each time a script runs. and we can assign a value to them.

DATA TYPES

  1. Numeric Data

  2. String Data

  3. Boolean Data

Arrays

  • arrays is a special type of variable it can store a list of value

  • the numbering of this list in the arrays starts at zero

EXPRESSIONS

  • Expressions evaluates into in a single value

  • there are two types of expressions:

  1. Expressions that assign value to a variable
  2. Expressions that use two or more values to return a single value
  • Expressions rely on things called operators they allow to create a single value from one or more values

type of operators

  • ARITHMETI C OPERATORS
  • STRING OPERATOR

Decision making

  • there are places in the script where desisions are made that determine which line of code should run

  • there are two components to a decision

  1. an expression is evaluated which returns a value
  2. a conditional statment says what to do in a fiven situation

  • we can compare one value in the script to what expect it will be the result will be boolean true or false

  • logical operators return a single value of true or false and allow to compare the result of more than one comparison operator

  • the if statment checks a condition that evaluate to a true or false to run the block of code based on the condition