Sophie: php-manual-en-4.3.0-2mdk noarch

php-manual-en-4.3.0-2mdk.noarch.rpm

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>empty</H1
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><P
>    (PHP 3, PHP 4 )</P
>empty&nbsp;--&nbsp;Determine whether a variable is set</DIV
><DIV
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><H2
>Description</H2
>bool <B
CLASS="methodname"
>empty</B
> ( mixed var)<BR
></BR
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><P
><B
>Note: </B
>
      <B
CLASS="function"
>empty()</B
> is a language construct.
     </P
></BLOCKQUOTE
></DIV
><P
>&#13;     This is the opposite of
     <TT
CLASS="literal"
>(boolean) <TT
CLASS="parameter"
><I
>var</I
></TT
></TT
>,
     except that no warning is generated when the variable is not set.
     See <A
HREF="language.types.boolean.html#language.types.boolean.casting"
>converting
     to boolean</A
> for more information.
    </P
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><PRE
CLASS="php"
>$var = 0;

if (empty($var)) {  // evaluates true
    echo '$var is either 0 or not set at all';
}

if (!isset($var)) { // evaluates false
    echo '$var is not set at all';
}</PRE
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>&#13;     Note that this is meaningless when used on anything which isn't a
     variable; i.e. <B
CLASS="command"
>empty (addslashes ($name))</B
> has
     no meaning since it would be checking whether something which
     isn't a variable is a variable with a <TT
CLASS="constant"
><B
>FALSE</B
></TT
> value.
     
    </P
><P
>&#13;     See also <A
HREF="function.isset.html"
><B
CLASS="function"
>isset()</B
></A
> and
     <A
HREF="function.unset.html"
><B
CLASS="function"
>unset()</B
></A
>.
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