EDA (Exploratory Data Analysis) focuses on exploring patterns and relationships in the data. It is an approach to analyzing data sets to summarize their main characteristics, often with visual methods.

The transformation method can make the distribution more symmetrical by pulling in extreme values.

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

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

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

If the file specified in the fwrite() function does not exist, PHP will automatically create a new file with the specified name and then write to it. This allows you to create a file on-the-fly when writing data to it using the fwrite() function.

The functions fread() and file_get_contents() can be used to read the contents of a file in PHP. fread() reads a file using a file pointer obtained from fopen(), while file_get_contents() reads the entire file into a string. The other options mentioned are not specifically used for reading file contents.

In PHP, a line of code is terminated with a semicolon (;). The semicolon is a statement separator and it's necessary to end a statement before starting a new line with a new statement. This makes the code easier to read and understand. Learn more: https://www.php.net/manual/en/language.basic-syntax.instruction-separation.php

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.

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

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.

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