Which of the following are common uses of the json_encode() and json_decode() functions in PHP?

Serializing PHP data into a JSON string
Deserializing a JSON string into PHP data
Interchanging data between PHP and JavaScript
All of the above

The json_encode() and json_decode() functions in PHP have multiple common uses. They are used for serializing PHP data into a JSON string, deserializing a JSON string into PHP data, and interchanging data between PHP and JavaScript applications. The correct option is "All of the above" as all the mentioned uses are valid and common. For more details, refer to the PHP documentation on json_encode(): http://php.net/manual/en/function.json-encode.php and json_decode(): http://php.net/manual/en/function.json-decode.php

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How is the ternary conditional operator used in PHP?

The ternary conditional operator in PHP is used as a shorthand for an if-else statement. It has the syntax: condition ? value_if_true : value_if_false;
The ternary conditional operator in PHP is used to perform arithmetic operations on two values.
The ternary conditional operator in PHP is used to concatenate strings based on a condition.
The ternary conditional operator in PHP is used to compare two values and return a boolean result.

The ternary conditional operator in PHP is used as a shorthand for an if-else statement. It allows you to conditionally choose between two values based on a condition. The syntax is condition ? value_if_true : value_if_false;. If the condition evaluates to true, the value before the : is returned; otherwise, the value after the : is returned. For example, $message = $isLogged ? "Welcome back!" : "Please log in"; assigns the value "Welcome back!" to $message if $isLogged is true, and "Please log in" otherwise. The ternary conditional operator can be used to simplify code and make it more concise, especially when assigning values based on simple conditions. It's important to use the ternary conditional operator judiciously to maintain code readability and avoid excessive nesting or complex conditions.

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What is the purpose of the array_reverse() function in PHP?

To reverse the order of elements in an array
To sort the elements of an array in reverse order
To filter the elements of an array
To remove duplicate values from an array

The array_reverse() function in PHP is used to reverse the order of elements in an array. It returns a new array with the elements in reverse order. This function is useful when you need to traverse an array in reverse order or change the order of elements. Learn more: http://php.net/manual/en/function.array-reverse.php

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How are variables in PHP declared?

Using let
Using var
Using $
Using declare

In PHP, variables are declared by preceding the variable name with a dollar sign ($). For example, $variable. PHP is a loosely typed language, which means that you don't have to declare the data type of a variable when you create it. Learn more: https://www.php.net/manual/en/language.variables.basics.php

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You have a PHP script and you need to extend an abstract class. How would you do this?

class ChildClass
class ChildClass extends
class ChildClass inherits
class ChildClass from

To extend an abstract class in PHP, you can use the extends keyword followed by the name of the abstract class. For example: class ChildClass extends AbstractClass {} The extends keyword indicates that the child class inherits the properties and methods of the abstract class. The child class can provide its own implementations for abstract methods and can also override non-abstract methods if needed. By extending the abstract class, the child class inherits the structure and functionality defined in the abstract class. For more details, visit: http://php.net/manual/en/language.oop5.abstract.php

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In PHP, an array can only hold values of the same data type.

TRUE
FALSE

This statement is false. In PHP, an array can hold values of different data types. PHP allows you to store elements of different data types, such as integers, floats, strings, or even other arrays, within the same array variable. This flexibility makes arrays powerful and versatile for managing collections of related data. Learn more: https://www.php.net/manual/en/language.types.array.php

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How can you open a file in PHP?

open()
fopen()
read()
include()

In PHP, you can open a file using the fopen() function. This function takes the file path and mode as arguments and returns a file pointer that can be used for further file operations, such as reading or writing.

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What function do you use in PHP to execute a query against a MySQL database?

mysqli_query()
mysql_query()
pdo_query()
execute_query()

In PHP, you can use the mysqli_query() function to execute a query against a MySQL database. This function takes two parameters: the connection object and the SQL query you want to execute. The SQL query can be any valid MySQL statement, such as SELECT, INSERT, UPDATE, or DELETE. The mysqli_query() function returns a result object for successful SELECT queries or a boolean value for other types of queries. It's important to use prepared statements or proper escaping techniques to prevent SQL injection vulnerabilities when executing user-supplied data as part of the query.

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In PHP, the ______ function is used to replace some characters in a string with some other characters.

str_replace()
replace()
substr_replace()
swap()

The str_replace() function in PHP is used to replace some characters in a string with some other characters. It performs a search and replace operation on a given string. It replaces all occurrences of the specified search string with the replacement string. Learn more: https://www.php.net/manual/en/function.str-replace.php

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A constructor in a PHP class is defined using the __construct() method.

method
function
keyword
property

In PHP, a constructor in a class is defined using the __construct() method. The correct option is "method." The __construct() method is a special method that is automatically called when an object of the class is created. It is used to initialize the object's properties or perform any necessary setup tasks. For further details, refer to the PHP documentation on constructors: http://php.net/manual/en/language.oop5.decon.php

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How do you define a destructor in a PHP class?

Using the __destruct() method
Using the destroy() method
Using the delete() method
Using the finalize() method

In PHP, you can define a destructor in a class using the __destruct() method. The correct option is "Using the __destruct() method." This special method is automatically called when an object is no longer referenced or explicitly destroyed. It is used to perform any necessary cleanup tasks or deallocate resources held by the object. For further details, refer to the PHP documentation on destructors: https://www.php.net/manual/en/language.oop5.decon.php#language.oop5.decon.destruct

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You are writing a PHP script and you need to filter multiple inputs. How would you do this?

Use the filter_input_array() function with the appropriate filters and input types
Use the filter_var_array() function with the appropriate filters and input types
Loop through the input values and apply the desired filters and validations individually
All of the above

To filter multiple inputs in a PHP script, you can use either the filter_input_array() function or the filter_var_array() function. Both functions allow you to specify the filters and input types to apply to the multiple inputs. You can loop through the input values and apply the desired filters and validations individually as well. All of the mentioned options are valid approaches to filter multiple inputs in PHP. For further details, refer to the PHP documentation on filter_input_array() (http://php.net/manual/en/function.filter-input-array.php) and filter_var_array() (http://php.net/manual/en/function.filter-var-array.php).

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