MATLAB clear vs. clear all

In MATLAB, the clear function is used to “remove items from workspace, freeing up system memory”¹, and it accepts some following options, such as clear all.

The command clear is to “remove all variables from the current workspace, releasing them from system memory”¹, that is, it can only clear all variables in the current workspace, whereas clear all can remove more items¹:

As can be seen, clear all seem not recommended as it will decrease the code performance and is usually unnecessary. Having said that, it is useful in some special cases, for example when we use the inmem function to test the dependencies of a function² — in this case, clear all creates a very clean workspace to help us obtain the minimal dependency information.

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