persistent()

Programming

persistent() is a MATLAB®-compatible programming function for declare variables that retain their values between calls to the same function. initialise to `[]` on first declaration; check with `isempty()`. Run it online in your browser with SimLab — free, no install, no license required.

Declare variables that retain their values between calls to the same function. Initialise to `[]` on first declaration; check with `isempty()`.

Syntax

persistent x
persistent x y z

Examples — run persistent() in your browser

function n = counter()
  persistent count
  if isempty(count); count = 0; end
  count = count + 1;
  n = count;
end
▶ Run

See Also

Frequently Asked Questions about persistent()

Is the persistent() function free to use in SimLab?

Yes. SimLab is 100% free — no signup, no license, and no usage limits. You can run persistent() and 510+ other MATLAB®-compatible functions directly in your browser at simulations4all.com/simlab.

Do I need to install MATLAB to use persistent()?

No. SimLab runs entirely in your web browser with zero installation. The persistent() function works without any MATLAB® license or software download.

What does persistent() do?

Declare variables that retain their values between calls to the same function. Initialise to `[]` on first declaration; check with `isempty()`. It is a MATLAB®-compatible programming function available in SimLab with the same calling syntax as MATLAB® — typically: persistent x.

Can I run persistent() in my browser?

Yes. Open SimLab at simulations4all.com/simlab, write or paste code that calls persistent(), and run it. Execution happens locally in your browser — no data leaves your machine.

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