Prompt $-$

Complete required steps:

$1.$ Create a single$-$line comment at the top of your PHP file that explains the purpose of the script.

$2.$ Write a PHP script that uses the 'echo' statement to display the following message on the screen: "Hello, World!"

$3.$ Write a PHP script that concatenates two strings together and displays the resulting string. The first string should be "Hello" and the second string should be "world!".

$4.$ Write a PHP script that declares a string variable named $\text{'}$$name' and assigns it the value "John". Display the string "Hello, John!" using string concatenation.

$5.$ Write a PHP script that declares a string variable named $\text{'}$$nullString' and assigns it the value 'null'. Display the string value.

$6.$ Write a PHP script that declares two integer variables and performs a numeric expression with them. Display the result of the expression on the screen. Add multi$-$line comments to explain what the code block does.

$7.$ Write a PHP script that declares an integer variable named $\text{'}$$num' and increments it by one using the $\text{'}++\text{'}$ operator. Display the new value of the variable on the screen. Then, decrement the variable by one using the $\text{'}--\text{'}$ operator and display the new value again.

$8.$ Declare two integer variables $\text{'}$$a$\text{'}$ and $\text{'}$$b$\text{'}$ with the values $10$ and $5$ respectively. Add them together and print the result.

$9.$ Declare two floating$-$point variables $\text{'}$$c$\text{'}$ and $\text{'}$$d$\text{'}$ with the values $2\mathrm{.}5$ and $1\mathrm{.}2$ respectively. Multiply them together and print the result.

$10.$ Declare two integer variables $\text{'}$$g and $h$\text{'}$ with the values $20$ and $3$ respectively. Divide $\text{'}$$g$\text{'}$ by $\text{'}$$h$\text{'}$ and print the result.