Code cleanup explained

Code cleanup refers to the act of writing so that it cleans up leftover and other unwanted materials from memory and the filesystem. It is sometimes treated as a synonym of refactoring code, which involves making the source code itself easier to understand, maintain, and modify.^[1]

Examples

C++

In C++, code cleanup involves deallocating previously allocated dynamic memory.

This is usually done with the C++ delete and delete[] operations.^[2]

int x = 15;int* mySequence = new int[x];for (int i = 0; i < x; i++) mySequence[0] = -127;delete[] mySequence;

Python

In Python 3, explicit deletion of variables requires the del keyword.^[3]

x = 15my_sequence = [0 for useless_variable in range(x)]my_sequence[0] = -127del my_sequence

JavaScript

In JavaScript, objects are garbage collected if they are unreachable from the global object.^[4] One way to make an object unreachable is to overwrite the variables or properties that reference it.

let x = ; // The variable x is declared and set to an objectx = null; // x is overwritten and the object becomes unreachable

Java

In Java, variables cannot be truly deleted. The most that can be done is to set the variable to null, which works with any Java object, including arrays.^[5]

int x = 15;int[] my_sequence = new int[x];for (int i = 0; i < x; i++) my_sequence[0] = -127;my_sequence = null;

Other meanings

Code cleanup can also refer to the removal of all computer programming from source code, or the act of removing temporary files after a program has finished executing.

For instance, in a web browser such as Chrome browser or Maxthon, code must be written in order to clean up files such as cookies and storage.^[6] The deletion of temporary files is similar to the deletion of unneeded lists and arrays of data. However, a file is treated as a permanent way to store a resizable list of bytes, and can also be removed from existence.^[7]

Loop cleanup

Another technical term sometimes called "code cleanup" is loop cleanup.

/* 'The i++ part is the cleanup for the for loop.' */for i = 0; i < 100; i++ print iend

import typelist = [10, 20, 30, 40, 50]/* 'Even in a for each loop, code cleanup with an incremented variable is still needed.' */i = 0for each element of list list[i] ^= 2 // 'Squares the element.' print string(element) + " is now... " + string(list[i]) i++end

Other Resources

• HTML Code Cleanup
• Formatting and Cleaning Up Code
• Resharper Code Cleanup
• Code Formatter

Notes and References

1. Web site: Microsoft Talks Code Cleanup. 15 December 2015 .
2. Web site: Code cleanup in C++.
3. Web site: Deletion of Variables in Python.
4. Web site: Memory Management - Mark-and-sweep algorithm.
5. Web site: Null in Java: The Pointer to Address 0.
6. Web site: DOM Storage - MDN. 26 July 2024 .
7. Web site: Erasing Cookies and Temporary Files in Google Chrome - Google.com.