Which of the following is NOT a valid PHP comparison operator?

What does the PHP statement echo 'Hello, World!'; do?

A). Prints 'Hello, World!' to the browser

B). Declares a variable named 'Hello, World!'

C). Performs a calculation

D). Defines a function named 'Hello, World!'

Which of the following is NOT a valid PHP variable name?

A). $my_var

B). $MyVar

C). $my-var

D). $myVar123

Which of the following statements is true about PHP arrays?

A). PHP arrays can hold values of different data types

B). PHP arrays must have continuous index values

C). PHP arrays are immutable

D). PHP arrays can only store integers

Which of the following symbols is used to concatenate strings in PHP?

A). +

B). <>

C). .

D). -

What is the purpose of the PHP include statement?

A). To include and evaluate an external PHP file

B). To create a loop in PHP

C). To define a function in PHP

D). To execute a SQL query

What is the correct way to define a constant in PHP?

A). define('MY_CONST', 'value');

B). $MY_CONST = 'value';

C). const MY_CONST = 'value';

D). MY_CONST = 'value';

Which of the following is true about PHP comments?

A). Comments are ignored by the PHP interpreter

B). Comments can only be single-line

C). Comments must start with /* and end with */

D). Comments are displayed on the webpage

What does the strlen() function do in PHP?

A). Returns the length of a string

B). Converts a string to lowercase

C). Checks if a string contains a substring

D). Returns the first occurrence of a substring in a string

What is the correct syntax to start a PHP script?

A). <?php

B). <script>

C). <?>

D). <!DOCTYPE php>

What does the phpinfo() function do in PHP?

A). Displays information about the PHP environment

B). Executes SQL queries

C). Validates user input

D). Encrypts data transmission