When accepting user file uploads, one should never trust the file's ________ as it can be easily spoofed.
- Extension
- Size
- Content-Type
- Location
Trusting the file extension is risky, as attackers can easily change it. It's better to verify the file's content and use other security measures.
Given the PHP expression $a && $b, if $a is false, what can be said about the evaluation of $b?
- $b will not be evaluated
- $b will be evaluated
- $b will always be false
- $b will always be true
In a logical AND (&&) expression, if the left operand ($a) is false, PHP does not evaluate the right operand ($b). This is called "short-circuiting" and is useful for efficiency and avoiding errors.
In PHP, the ________ function can be used to return a part of a string.
- substr()
- split()
- slice()
- cut()
The 'substr()' function in PHP is used to extract a portion of a string. It takes the original string and specifies the start and length of the substring to be returned.
You are developing a RESTful API in PHP and want to ensure that the response is always in JSON format. Which PHP function would you primarily use to convert the data to this format?
- json_encode()
- json_decode()
- serialize()
- unserialize()
The json_encode() function in PHP is used to convert data to JSON format. It's essential for generating JSON responses in a RESTful API.
To check the data type of a variable in PHP, which function is used?
- is_type()
- gettype()
- datatype()
- typeof()
To check the data type of a variable in PHP, you use the gettype() function. This function returns a string indicating the data type of the variable, such as "integer," "string," or "array."
You are working on a project where certain methods in your classes should only be defined but not implemented, and the actual implementation should be provided by the derived classes. Which PHP concept helps achieve this?
- Interface
- Trait
- Abstract Class
- Final Class
An interface defines method signatures without implementations. Derived classes that implement the interface must provide the implementation for those methods. This is a common approach in PHP to achieve this requirement.
Which of the following is a common best practice when writing PHP functions?
- Use global variables extensively
- Make functions as long as possible
- Provide meaningful function names
- Avoid using return statements inside
Giving functions meaningful names is essential for code readability and maintainability, a best practice in writing PHP functions.
To remove white spaces from the beginning and end of a string, you would use the ________ function in PHP.
- trim()
- remove_spaces()
- strip_whitespaces()
- clean_string()
The trim() function in PHP is used to remove white spaces from both the beginning and the end of a given string, making it useful for data cleaning.
When using PDO, which method fetches the next row from a result set?
- fetch()
- fetchNext()
- fetchRow()
- getNextRow()
The fetch() method in PDO is used to fetch the next row from a result set. It allows you to retrieve data from the result set one row at a time, facilitating efficient handling of large datasets.
In the context of PHP, what does the acronym "DRY" stand for?
- Don't Repeat Yourself (DRY)
- Data Retrieval Yield
- Document Representation Yields
- Development Reuse Yield
In PHP, "DRY" stands for "Don't Repeat Yourself," a programming principle that emphasizes reusing code to avoid redundancy and improve maintainability.
When dealing with form data in PHP, which function can be used to check if a particular input filter is supported?
- filter_has_var()
- validate_input()
- check_input_filter()
- is_filter_supported()
The filter_has_var() function is used to check if a particular input filter is supported for a specific form input. This is essential for input validation in PHP.
A developer wants to store multiple values in a single variable. Which of the following data types in PHP should he/she use?
- Array
- String
- Integer
- Object
To store multiple values in a single variable, an array should be used in PHP. Arrays can hold various data types and are versatile for handling collections of data.