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The result is the Boolean complement of the operand value.
The exclamation mark is the logical negation operator. The operand is evaluated and its result converted to a binary value. The value is then reversed and used to replace the expression in whatever context it has been used.
The truth table shows the result of this operator for a Boolean primitive value:
Although this is classified as a logical operator here, it is also classified as a unary operator since it only has one operand.
The associativity is from right to left.
Refer to the operator precedence topic for details of execution order.
<HTML>
<HEAD></HEAD>
<BODY>
<TABLE BORDER=1 CELLPADDING=2>
<TR>
<TH>A</TH>
<TH>NOT</TH>
</TR>
<SCRIPT>
for(a=0; a<2; a++)
{
document.write("<TR ALIGN=CENTER><TD>");
document.write(Boolean(a));
document.write("</TD><TD>");
document.write(Boolean(!a));
document.write("</TD></TR>");
}
</SCRIPT>
</TABLE>
</BODY>
</HTML>| Prev | Home | Next |
| Logical expression | Up | Logical operator |
JavaScript Programmer's Reference, Cliff Wootton Wrox Press (www.wrox.com) Join the Wrox JavaScript forum at p2p.wrox.com Please report problems to support@wrox.com © 2001 Wrox Press. All Rights Reserved. Terms and conditions. | ||