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

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><TT
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>foreach</TT
></H1
><P
>&#13;    PHP 4 (not PHP 3) includes a <TT
CLASS="literal"
>foreach</TT
> construct, much
    like Perl and some other languages. This simply gives an easy way to
    iterate over arrays. <TT
CLASS="literal"
>foreach</TT
> works only on arrays, and
    will issue an error when you try to use it on a variable with a different
    data type or an uninitialized variables. There are two syntaxes; the
    second is a minor but useful extension of the first:
    <DIV
CLASS="informalexample"
><A
NAME="AEN4961"
></A
><P
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><PRE
CLASS="programlisting"
>foreach(array_expression as $value) statement
foreach(array_expression as $key =&#62; $value) statement</PRE
></TD
></TR
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><P
></P
></DIV
>
   </P
><P
>&#13;    The first form loops over the array given by
    <TT
CLASS="literal"
>array_expression</TT
>. On each loop, the value of
    the current element is assigned to <TT
CLASS="literal"
>$value</TT
> and
    the internal array pointer is advanced by one (so on the next
    loop, you'll be looking at the next element).
   </P
><P
>&#13;    The second form does the same thing, except that the current
    element's key will be assigned to the variable
    <TT
CLASS="literal"
>$key</TT
> on each loop.
   </P
><P
>&#13;    <DIV
CLASS="note"
><BLOCKQUOTE
CLASS="note"
><P
><B
>Note: </B
>
      When <TT
CLASS="literal"
>foreach</TT
> first starts executing, the
      internal array pointer is automatically reset to the first element
      of the array. This means that you do not need to call
      <A
HREF="function.reset.html"
><B
CLASS="function"
>reset()</B
></A
> before a <TT
CLASS="literal"
>foreach</TT
>
      loop.
     </P
></BLOCKQUOTE
></DIV
>
   </P
><P
>&#13;    <DIV
CLASS="note"
><BLOCKQUOTE
CLASS="note"
><P
><B
>Note: </B
>
      Also note that <TT
CLASS="literal"
>foreach</TT
> operates on a copy of
      the specified array, not the array itself, therefore the array
      pointer is not modified as with the <A
HREF="function.each.html"
><B
CLASS="function"
>each()</B
></A
>
      construct and changes to the array element returned are not
      reflected in the original array.  However, the internal pointer
      of the original array <SPAN
CLASS="emphasis"
><I
CLASS="emphasis"
>is</I
></SPAN
> advanced with
      the processing of the array.  Assuming the foreach loop runs
      to completion, the array's internal pointer will be at the
      end of the array.
     </P
></BLOCKQUOTE
></DIV
>
   </P
><DIV
CLASS="note"
><BLOCKQUOTE
CLASS="note"
><P
><B
>Note: </B
>
     <TT
CLASS="literal"
>foreach</TT
> does not support the ability to
     suppress error messages using '@'.
    </P
></BLOCKQUOTE
></DIV
><P
>&#13;    You may have noticed that the following are functionally
    identical:
    <DIV
CLASS="informalexample"
><A
NAME="AEN4984"
></A
><P
></P
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><PRE
CLASS="php"
>reset ($arr);
while (list(, $value) = each ($arr)) {
    echo "Value: $value&#60;br&#62;\n";
}

foreach ($arr as $value) {
    echo "Value: $value&#60;br&#62;\n";
}</PRE
></TD
></TR
></TABLE
><P
></P
></DIV
>
    The following are also functionally identical:
    <DIV
CLASS="informalexample"
><A
NAME="AEN4986"
></A
><P
></P
><TABLE
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><PRE
CLASS="php"
>reset ($arr);
while (list($key, $value) = each ($arr)) {
    echo "Key: $key; Value: $value&#60;br&#62;\n";
}

foreach ($arr as $key =&#62; $value) {
    echo "Key: $key; Value: $value&#60;br&#62;\n";
}</PRE
></TD
></TR
></TABLE
><P
></P
></DIV
>
   </P
><P
>&#13;    Some more examples to demonstrate usages:
    <DIV
CLASS="informalexample"
><A
NAME="AEN4989"
></A
><P
></P
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><PRE
CLASS="php"
>/* foreach example 1: value only */

$a = array (1, 2, 3, 17);

foreach ($a as $v) {
   print "Current value of \$a: $v.\n";
}

/* foreach example 2: value (with key printed for illustration) */

$a = array (1, 2, 3, 17);

$i = 0; /* for illustrative purposes only */

foreach($a as $v) {
    print "\$a[$i] =&#62; $v.\n";
    $i++;
}

/* foreach example 3: key and value */

$a = array (
    "one" =&#62; 1,
    "two" =&#62; 2,
    "three" =&#62; 3,
    "seventeen" =&#62; 17
);

foreach($a as $k =&#62; $v) {
    print "\$a[$k] =&#62; $v.\n";
}

/* foreach example 4: multi-dimensional arrays */

$a[0][0] = "a";
$a[0][1] = "b";
$a[1][0] = "y";
$a[1][1] = "z";

foreach($a as $v1) {
    foreach ($v1 as $v2) {
        print "$v2\n";
    }
}

/* foreach example 5: dynamic arrays */

foreach(array(1, 2, 3, 4, 5) as $v) {
    print "$v\n";
}</PRE
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