Which predefined PHP function is used to find the position of the first occurrence of a substring?
- strpos($string, $substring)
- strfind($string, $substring)
- strstrpos($string, $substring)
- locate($substring, $string)
The correct option is 'strpos($string, $substring)'. It is used to find the position of the first occurrence of a substring within a string. The other options are incorrect functions.
How can you remove the first element from an array in PHP?
- array_shift()
- array_pop()
- unset()
- array_slice($array, 1)
The array_shift() function removes and returns the first element of an array, effectively shifting the array's keys.
PHP is loosely typed, meaning:
- Data types are strictly enforced
- Data types are dynamically determined
- Data types are not used in PHP
- Data types are implicitly cast
PHP is loosely typed, meaning that data types are dynamically determined by the context in which they are used. Variables can change their data type as needed.
To ensure that an email field contains a valid email address, you can use the PHP ________ filter.
- sanitize_email()
- validate_email()
- filter_var()
- check_email()
You can use the PHP filter_var() function with the FILTER_VALIDATE_EMAIL filter to ensure that an email field contains a valid email address.
Which of the following is the correct way to define an associative array in PHP?
- $colors = ['red' => '#FF0000', 'green' => '#00FF00', 'blue' => '#0000FF']
- $colors = ['red', 'green', 'blue']
- $colors = ('red' => '#FF0000', 'green' => '#00FF00', 'blue' => '#0000FF')
- $colors = {'red' => '#FF0000', 'green' => '#00FF00', 'blue' => '#0000FF'}
The correct way to define an associative array in PHP is by using the format shown in Option 1, where keys are associated with values using the => symbol.
Which of the following best describes "defensive programming" in the context of PHP?
- Writing code that anticipates and handles errors
- Writing code that aggressively catches and suppresses all errors
- Writing code that relies on system error messages to identify issues
- Writing code that creates intentional vulnerabilities for testing purposes
Defensive programming in PHP involves writing code that anticipates and handles errors, aiming to make the code robust and resilient to unexpected issues.
How can you include a file from another namespace without using its fully qualified name?
- use statement
- include statement
- require statement
- namespace keyword
You can include a file from another namespace without using its fully qualified name by using the use statement. It allows you to alias namespaces or import classes/functions into the current namespace.
Imagine you are building an e-commerce application. When a user places an order, multiple operations like updating stock, logging order details, and processing payments are involved. Why would using transactions be beneficial in this scenario?
- To ensure data consistency
- To reduce database size
- To speed up data retrieval
- To simplify application code
Using transactions ensures that all the operations are treated as a single unit. If any part of the transaction fails, the entire transaction is rolled back, maintaining data consistency.
Which of the following headers can help in mitigating CSRF attacks?
- Content-Type
- X-Content-Security-Policy
- Referer-Policy
- X-Requested-With
The Referer-Policy header can help mitigate Cross-Site Request Forgery (CSRF) attacks by controlling which origins are allowed to make requests to the resource.
The path for which the cookie is valid can be set using the ________ parameter in the setcookie() function.
- cookie.max_age
- cookie.secure
- cookie.expires
- cookie.path
The 'cookie.path' parameter in the setcookie() function defines the path for which the cookie is valid, allowing for precise control over cookie scope.