Code cleanup refers to the act of writing so that it cleans up leftover and other unwanted materials from memory and the filesystem.
[1] In C++, code cleanup involves deallocating previously allocated dynamic memory.
[2] In Python 3, explicit deletion of variables requires the del keyword.
The most that can be done is to set the variable to null, which works with any Java object, including arrays.
However, a file is treated as a permanent way to store a resizable list of bytes, and can also be removed from existence.