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<h3 class="section">5.7 Exclamation mark as not operator</h3>
<p>The exclamation mark ‘<samp><span class="samp">!</span></samp>’ (aka “Bang!”) is a negation operator, just
like the tilde ‘<samp><span class="samp">~</span></samp>’:
<pre class="example"> octave:1> if ! strcmp (program_name, "octave"),
> "It's an error"
> else
> "It works!"
> end
ans = It works!
</pre>
<p class="noindent">Note however that <span class="sc">Matlab</span> uses the ‘<samp><span class="samp">!</span></samp>’ operator for shell
escapes, for which Octave requires using the <code>system</code> command.
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