Boolean values: Difference between revisions
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Underscore (talk | contribs) (→{{header|Perl}}: Expanded.) |
Underscore (talk | contribs) (Added Perl 6.) |
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Perl has no builtin "true" or "false" keywords. However, as a special case, literal <tt>1</tt>s and <tt>0</tt>s will never cause a "Useless use of a constant in void context" warning. Another special case worth pointing out here is that the string <tt>'0 but true'</tt> won't provoke a warning if it's used as a number. |
Perl has no builtin "true" or "false" keywords. However, as a special case, literal <tt>1</tt>s and <tt>0</tt>s will never cause a "Useless use of a constant in void context" warning. Another special case worth pointing out here is that the string <tt>'0 but true'</tt> won't provoke a warning if it's used as a number. |
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=={{header|Perl 6}}== |
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<!-- No "works with" because Bool isn't a proper role in Rakudo yet (as of release #22). --> |
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Perl 6 provides an enumeration <code>Bool</code> with two values, <code>True</code> and <code>False</code>. Values of enumerations can be used as ordinary values or as mixins: |
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<lang perl6>my Bool $crashed = False; |
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my $val = 0 but True;</lang> |
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For a discussion of Boolean context (i.e. how Perl decides whether something is true or false), see [http://perlcabal.org/syn/S02.html#Context Synopsis 2]. |
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=={{header|PHP}}== |
=={{header|PHP}}== |