Which of the following are true about indexed arrays in PHP?
- Indexed arrays use string keys to access elements.
- Indexed arrays preserve the order of elements.
- Indexed arrays can have elements of different data types.
- Indexed arrays can only store a single value.
The correct option is 2. Indexed arrays in PHP use numeric keys to access elements, not string keys. Indexed arrays preserve the order of elements, allowing for sequential access. Indexed arrays can indeed store elements of different data types, including strings, integers, floats, booleans, and even other arrays. Indexed arrays can store multiple values and are a versatile data structure in PHP. Learn more: https://www.php.net/manual/en/language.types.array.php#language.types.array.syntax
Which PHP function is used to create a constant?
- define()
- var()
- constant()
- assign()
The define() function in PHP is used to create a constant. It takes two arguments: the constant name (identifier) and its value. Once defined, constants cannot be changed or redefined during the execution of the script. They provide a way to store fixed values that remain the same throughout the script's execution. Learn more: https://www.php.net/manual/en/function.define.php
The switch statement in PHP is used to select one of many blocks of code to be executed.
- Executed
- Evaluated
- Compared
- Skipped
The switch statement in PHP is used to select one of many blocks of code to be executed. It provides a way to simplify code when you have multiple possible conditions to evaluate. The switch statement takes an expression as input and checks it against a series of case values. When a case value matches the expression, the corresponding block of code is executed. This allows you to perform different actions based on the value of the expression without the need for multiple if-else statements. Learn more: https://www.php.net/manual/en/control-structures.switch.php
The value of a class constant in PHP cannot be changed once it is ______.
- defined
- accessed
- assigned
- declared
The value of a class constant in PHP cannot be changed once it is assigned. Once a constant is defined with a specific value, it remains the same throughout the execution of the script. Constants are considered as read-only values. It's important to note that attempting to modify a constant's value will result in a runtime error. To maintain the immutability of constant values, it is recommended to define them with the desired value and avoid any attempts to modify them later. To know more, refer to: http://php.net/manual/en/language.constants.php
To get the list of all supported filters in PHP, you can use the filter_list() ______.
- function
- filters
- types
- supported
To get the list of all supported filters in PHP, you can use the filter_list() function. It returns an array containing the names of all available filters. Learn more at: http://php.net/manual/en/function.filter-list.php
A destructor in a PHP class is called when the object is no longer referenced or explicitly destroyed.
- no longer referenced or explicitly destroyed
- instantiated from the class
- accessed
- methods invoked
A destructor in a PHP class is called when the object is no longer referenced or explicitly destroyed. The correct option is "no longer referenced or explicitly destroyed." The destructor is automatically triggered by PHP's garbage collection mechanism when there are no more references to the object, or when the unset() function is used to explicitly destroy the object. This allows the destructor to perform any necessary cleanup tasks before the object is freed from memory. For more details, refer to the PHP documentation on destructors: https://www.php.net/manual/en/language.oop5.decon.php#language.oop5.decon.destruct
The filter_var_array() function allows you to filter multiple inputs at once in PHP.
- single
- multiple
- individual
- specific
The filter_var_array() function in PHP allows you to filter multiple inputs at once. It takes an input array and applies a specified filter to each element of the array. For further information, visit: http://php.net/manual/en/function.filter-var-array.php
What are some common practices in PHP when using static methods in OOP?
- Use static methods sparingly and only for functionality that doesn't rely on object state.
- Avoid using static methods excessively, as it can make code less modular and harder to test.
- Ensure static methods are stateless and do not modify shared data.
- All of the above
When using static methods in PHP OOP, it is recommended to use them sparingly and only for functionality that doesn't rely on object state. Excessive use of static methods can make code less modular and harder to test. It's important to ensure that static methods are stateless and do not modify shared data, as it can lead to unexpected behavior in a multi-threaded or concurrent environment. Following these practices helps maintain the maintainability and flexibility of the codebase.
In PHP, you can define a class using the class keyword followed by the class name like class ______.
- Name
- ClassName
- ObjectName
- Type
In PHP, you can define a class using the class keyword followed by the desired name of the class. The correct option is "ClassName." The class name should be a valid identifier and follow the naming conventions. For more details, refer to the PHP documentation on defining classes: http://php.net/manual/en/language.oop5.php
What is the meaning of a final class and a final method?
- A final class is a class that cannot be inherited or extended by other classes.
- A final class is a class that can only be accessed from within the same package.
- A final class is a class that can only have one instance and cannot be instantiated multiple times.
- A final class is a class that can be overridden by subclasses.
In PHP, a final class is a class that cannot be inherited or extended by other classes. It is declared using the final keyword. Final classes are used when you want to prevent further extension or inheritance of a class. A final method, on the other hand, is a method within a class that cannot be overridden by any subclass. It is also declared using the final keyword. Final methods are used when you want to enforce that a specific method should not be overridden in any subclass.