difference between "and" and "&&"

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I thought the only difference between these was precedence, but I'm seeing
another difference.

a  test'
b  il
haveBoth   and b
# haveBoth is now equal to 'test'

haveBoth   && b
# haveBoth is now equal to nil

Is this the expected behavior?

What I want to do is verify that two strings are not nil.
It looks like I have to use "&&" instead of "and" to do that.


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<TITLE>difference between &quot;and&quot; and &quot;&amp;&amp;&quot;</TITLE>
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<P><FONT SIZE I thought the only difference between these was precedence, but I'm seeing another difference.</FONT>
</P>

<P><FONT SIZE a  test'</FONT>
<BR><FONT SIZE b  il</FONT>
<BR><FONT SIZE haveBoth   and b</FONT>
<BR><FONT SIZE # haveBoth is now equal to 'test'</FONT>
</P>

<P><FONT SIZE haveBoth   &amp;&amp; b</FONT>
<BR><FONT SIZE # haveBoth is now equal to nil</FONT>
</P>

<P><FONT SIZE Is this the expected behavior?</FONT>
</P>

<P><FONT SIZE What I want to do is verify that two strings are not nil.</FONT>
<BR><FONT SIZE It looks like I have to use &quot;&amp;&amp;&quot; instead of &quot;and&quot; to do that.</FONT>
</P>

<CODE><FONT SIZE0<BR>
<BR>
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