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

What is the purpose of the PHP print_r() function?

A). To print human-readable information about a variable

B). To redirect output to a file

C). To execute SQL queries

D). To define a function in PHP

What is the correct syntax to start a PHP script?

A). <?php

B). <script>

C). <?>

D). <!DOCTYPE php>

What is the purpose of the PHP unset() function?

A). To destroy a specified variable

B). To create an array in PHP

C). To execute SQL queries

D). To define a function in PHP

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

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 purpose of the PHP require statement?

A). To include and evaluate an external PHP file

B). To define a function in PHP

C). To create a loop in PHP

D). To execute a SQL query

What is the purpose of the PHP die() function?

A). To terminate the script execution and display a message

B). To print output to the browser

C). To create a loop in PHP

D). To define a function in PHP

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

A). +

B). <>

C). .

D). -

What is the purpose of the PHP require_once statement?

A). To include and evaluate an external PHP file only once

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';