Code cleanup

Code cleanup refers to the act of writing code so that it cleans up leftover data structures and other unwanted materials from memory and the filesystem. It is not the same as refactoring code, which involves making the source code itself easier to understand, maintain, and modify.

Examples

C++

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

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

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

Python

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

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

JavaScript

In JavaScript, deleting a variable requires the delete keyword.

var x = 15;
my_sequence = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
my_sequence[0] = -127;
delete my_sequence;

Mint

In Mint, variable deletion is known as erasing variables:

x = 15
my_sequence = []
repeat x
    my_sequence.add(0)
end
my_sequence[0] = -127
erase my_sequence

Mint also possesses the erase all except VARS operation, which erases all variables in all frames (scopes) except for the variables listed in the comma separated sequence VARS.

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.

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

Other Meanings

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

For instance, in a web browser such as Google Chrome or Maxthon, code must be written in order to clean up files such as cookies and HTML5 storage. 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.

Other Resources

HTML Code Cleanup
Formatting and Cleaning Up Code
Resharper Code Cleanup