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<head><title>mutable -- whether something may be modified</title>
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<div><a href="index.html" title="">Macaulay2Doc</a> > <a href="___The_sp__Macaulay2_splanguage.html" title="">The Macaulay2 language</a> > <a href="_hash_sptables.html" title="">hash tables</a> > <a href="_mutable.html" title="whether something may be modified">mutable</a></div>
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<div><h1>mutable -- whether something may be modified</h1>
<div class="single"><h2>Description</h2>
<div><tt>mutable x</tt> -- returns true or false, depending on whether x is mutable.<p/>
If <tt>x</tt> is a hash table, list, or database, then it's mutable if its contents can be destructively altered.<p/>
If <tt>x</tt> is a symbol, then it's mutable if a value can be assigned to it. (See <a href="_protect.html" title="protect a symbol">protect</a>.)<p/>
If <tt>x</tt> is anything else, then it isn't mutable.<p/>
The contents of a mutable hash table do not participate in strong comparison with <a href="___Thing_sp_eq_eq_eq_sp__Thing.html" title="strict equality">===</a> or in <a href="_hashing.html" title="">hashing</a>.</div>
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<div class="single"><h2>See also</h2>
<ul><li><span><a href="___Mutable__List.html" title="the class of all mutable lists">MutableList</a> -- the class of all mutable lists</span></li>
<li><span><a href="___Mutable__Hash__Table.html" title="the class of all mutable hash tables">MutableHashTable</a> -- the class of all mutable hash tables</span></li>
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<div class="waystouse"><h2>Ways to use <tt>mutable</tt> :</h2>
<ul><li>mutable(Thing)</li>
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