CScientists

How to download and install Visual Studio Code

Visual Studio Code is a code editor redefined and optimized for building and debugging modern web and cloud applications. Free. Built on open source. Runs everywhere.

Downloading:

Step 1: Open the following link.

https://code.visualstudio.com/

Step 2: Click download button (It depends on your Operating System). Then it will be downloaded automatically.

Installing: install it as following:

Printing your name in large letters

Q: Write a program that prints your name in large letters.

Product of the First Ten Positive Integers

Q: Write a program that prints the product of the first ten positive integers, 1 × 2 × … × 10. (Use * to indicate multiplication in Python.)

Balance of an Account

Q: Write a program that prints the
balance of an account after the first, second, and third year. The account has an initial balance of $1,000 and earns 5 percent interest per year.

balance = 1000
percent = 0.05
for i in range(1,4):
balance = balance+ balance*percent
print("The balacne after %d is %.2f"%(i,balance))

CSS How To

When a browser reads a style sheet, it will format the HTML document according to the information in the style sheet.

Three Ways to Insert CSS

There are three ways of inserting a style sheet:

External style sheet
Internal style sheet
Inline style

External Style Sheet

With an external style sheet, you can change the look of an entire website by changing just one file!

Each page must include a reference to the external style sheet file inside the <link> element. The <link> element goes inside the <head> section:

<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" type="text/css" href="mystyle.css">
</head>
<body>

<h1>This is a heading</h1>
<p>This is a paragraph.</p>

</body>
</html>

An external style sheet can be written in any text editor. The file should not contain any html tags. The style sheet file must be saved with a .css extension.

Here is how the "mystyle.css" looks:

body {
background-color: lightblue;
}

h1 {
color: navy;
margin-left: 20px;
}

Internal Style Sheet

An internal style sheet may be used if one single page has a unique style.

Internal styles are defined within the <style> element, inside the <head> section of an HTML page:

<head>
<style>
body {
background-color: linen;
}

h1 {
color: maroon;
margin-left: 40px;
}
</style>
</head>

Inline Styles

An inline style may be used to apply a unique style for a single element.

To use inline styles, add the style attribute to the relevant element. The style attribute can contain any CSS property.

The example below shows how to change the color and the left margin of a <h1> element:

<h1 style="color:blue;margin-left:30px;">This is a heading</h1>

Tip: An inline style loses many of the advantages of a style sheet (by mixing content with presentation). Use this method sparingly.

Multiple Style Sheets

If some properties have been defined for the same selector (element) in different style sheets, the value from the last read style sheet will be used.

Example

Assume that an external style sheet has the following style for the <h1> element:

h1 {
color: navy;
}

then, assume that an internal style sheet also has the following style for the <h1> element:

h1 {
color: orange;
}

If the internal style is defined after the link to the external style sheet, the <h1> elements will be "orange":

<head>
<link rel="stylesheet" type="text/css" href="mystyle.css">
<style>
h1 {
color: orange;
}
</style>
</head>

However, if the internal style is defined before the link to the external style sheet, the <h1> elements will be "navy":

<head>
<style>
h1 {
color: orange;
}
</style>
<link rel="stylesheet" type="text/css" href="mystyle.css">
</head>

Cascading Order

What style will be used when there is more than one style specified for an HTML element?

All the styles in a page will "cascade" into a new "virtual" style sheet by the following rules, where number one has the highest priority:

Inline style (inside an HTML element)
External and internal style sheets (in the head section)
Browser default

So, an inline style has the highest priority, and will override external and internal styles and browser defaults.

CSS Syntax

A CSS rule-set consists of a selector and a declaration block:

The selector points to the HTML element you want to style.

The declaration block contains one or more declarations separated by semicolons.

Each declaration includes a CSS property name and a value, separated by a colon.

A CSS declaration always ends with a semicolon, and declaration blocks are surrounded by curly braces.

In the following example all <p> elements will be center-aligned, with a red text color:

p {
color: red;
text-align: center;
}

CSS Selectors

CSS selectors are used to "find" (or select) HTML elements based on their element name, id, class, attribute, and more.

The element Selector

The element selector selects elements based on the element name.

You can select all <p> elements on a page like this (in this case, all <p> elements will be center-aligned, with a red text color):

p {
text-align: center;
color: red;
}

The id Selector

The id selector uses the id attribute of an HTML element to select a specific element.

The id of an element should be unique within a page, so the id selector is used to select one unique element!

To select an element with a specific id, write a hash (#) character, followed by the id of the element.

The style rule below will be applied to the HTML element with id="para1":

#para1 {
text-align: center;
color: red;
}

Note: An id name cannot start with a number!

The class Selector

The class selector selects elements with a specific class attribute.

To select elements with a specific class, write a period (.) character, followed by the name of the class.

In the example below, all HTML elements with class="center" will be red and center-aligned:

.center {
text-align: center;
color: red;
}

HTML elements can also refer to more than one class.

In the example below, the <p> element will be styled according to class="center" and to class="large":

<p class="center large">This paragraph refers to two classes.</p>

Note: A class name cannot start with a number!

Grouping Selectors

If you have elements with the same style definitions, like this:

h1 {
text-align: center;
color: red;
}

h2 {
text-align: center;
color: red;
}

p {
text-align: center;
color: red;
}

It will be better to group the selectors, to minimize the code.

To group selectors, separate each selector with a comma.

In the example below we have grouped the selectors from the code above:

h1, h2, p {
text-align: center;
color: red;
}

CSS Comments

Comments are used to explain the code, and may help when you edit the source code at a later date.

Comments are ignored by browsers.

A CSS comment starts with /* and ends with */. Comments can also span multiple lines:

p {
color: red;
/* This is a single-line comment */
text-align: center;
}

/* This is
a multi-line
comment */

PHP 7 echo and print Statements

In PHP there are two basic ways to get output: echo and print.

In this tutorial we use echo (and print) in almost every example. So, this chapter contains a little more info about those two output statements.

PHP echo and print Statements

echo and print are more or less the same. They are both used to output data to the screen.

The differences are small: echo has no return value while print has a return value of 1 so it can be used in expressions. echo can take multiple parameters (although such usage is rare) while print can take one argument. echo is marginally faster than print.

The PHP echo Statement

The echo statement can be used with or without parentheses: echo or echo().

Display Text

The following example shows how to output text with the echo command (notice that the text can contain HTML markup):

<?php
echo "<h2>PHP is Fun!</h2>";
echo "Hello world!<br>";
echo "I'm about to learn PHP!<br>";
echo "This ", "string ", "was ", "made ", "with multiple parameters.";
?>

Display Variables

The following example shows how to output text and variables with the echo statement:

<?php
$txt1 = "Learn PHP";
$txt2 = "W3Schools.com";
$x = 5;
$y = 4;

echo "<h2>" . $txt1 . "</h2>";
echo "Study PHP at " . $txt2 . "<br>";
echo $x + $y;
?>

The PHP print Statement

The print statement can be used with or without parentheses: print or print().

Display Text

The following example shows how to output text with the print command (notice that the text can contain HTML markup):

<?php
print "<h2>PHP is Fun!</h2>";
print "Hello world!<br>";
print "I'm about to learn PHP!";
?>