Open the Editor by typing:
edit
in the Command Window. Paste the code into an editor tab, save it by whatever name you want in your personal MATLAB directory (in Windows, this is C:\Users\<username>\Documents\MATLAB\), then run it.
How you run it is important, since if it is a function, it most likely needs to have input arguments (though not always, it depends on how the function wsas written), otherwise, typing its name in the Command Window or clicking on the green Run arrow in the Editor toolbar will both work.
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