clear — Clear variables from the active workspace.

clear removes variables from the active RunMat workspace. RunMat supports MATLAB-style clear, clear all, and named-variable forms such as clear x or clear x y, updating the session snapshot so removed variables disappear from subsequent workspace queries.

How clear works in RunMat

• clear with no inputs clears all workspace variables created in the current session.
• clear('all') and command-form clear all are treated the same as bare clear.
• clear x removes the variable x while leaving other workspace bindings intact.
• Multiple names can be supplied as separate inputs or command-form tokens, for example clear x y z.
• After a successful clear, removed variables are no longer available to later statements and the workspace snapshot is refreshed so hosts can drop cleared bindings.
• Accepts variable names as string scalars, row character vectors, or string arrays. If any input is all, the entire workspace is cleared.
• Clearing a name that does not exist is a no-op.
• clear is a sink builtin and does not produce a meaningful output value.

How clear runs on the GPU

clear performs host-side workspace mutation only. It does not launch GPU kernels, does not participate in fusion, and does not depend on acceleration providers.

Examples

Clear the entire interactive workspace

x = 1;
y = magic(3);
clear

Expected output:

% x and y are removed from the workspace

Use MATLAB-style command form

a = 42;
clear all

Expected output:

% a is removed from the workspace

Accessing a cleared variable raises an error

x = 7;
clear;
x

Expected output:

Undefined variable: x

Clear one variable while leaving others intact

x = 1;
y = 2;
clear x

Expected output:

% x is removed from the workspace while y remains defined

Clear multiple named variables in command form

a = 1;
b = 2;
c = 3;
clear a b

Expected output:

% a and b are removed; c remains defined

FAQ

Does clear remove every variable in the current session?

Bare clear and clear all clear the full workspace. Named forms such as clear x remove only the specified bindings.

Can I clear only one variable?

Yes. Use clear x or clear("x") to remove one variable, and pass multiple names to clear more than one binding in a single call.

Does clear return anything?

No meaningful value is returned. clear is a side-effecting builtin whose purpose is to mutate workspace state.

Does clear affect plotting state or the console?

No. clear only clears workspace variables. Use plotting commands such as close all for figures and clc for the visible console.

Does GPU residency matter?

No. clear operates on session bookkeeping, not on array kernels or provider-managed computations.

Related functions to explore

These functions work well alongside clear. Each page has runnable examples you can try in the browser.

who, whos, clc, close

Open-source implementation

Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how clear works, line by line, in Rust.

• View clear.rs on GitHub
• Learn how the runtime works
• Found a bug? Open an issue with a minimal reproduction.

About RunMat

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