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

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

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><H1
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><TT
CLASS="literal"
>for</TT
></H1
><P
>&#13;    <TT
CLASS="literal"
>for</TT
> loops are the most complex loops in PHP.
    They behave like their C counterparts.  The syntax of a
    <TT
CLASS="literal"
>for</TT
> loop is:
    <DIV
CLASS="informalexample"
><A
NAME="AEN4924"
></A
><P
></P
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><TD
><PRE
CLASS="programlisting"
>for (expr1; expr2; expr3) statement</PRE
></TD
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></TABLE
><P
></P
></DIV
>
   </P
><P
>&#13;    The first expression (<TT
CLASS="replaceable"
><I
>expr1</I
></TT
>) is
    evaluated (executed) once unconditionally at the beginning of the
    loop.
   </P
><P
>&#13;    In the beginning of each iteration,
    <TT
CLASS="replaceable"
><I
>expr2</I
></TT
> is evaluated.  If it evaluates to
    <TT
CLASS="constant"
><B
>TRUE</B
></TT
>, the loop continues and the nested
    statement(s) are executed.  If it evaluates to
    <TT
CLASS="constant"
><B
>FALSE</B
></TT
>, the execution of the loop ends.
   </P
><P
>&#13;    At the end of each iteration, <TT
CLASS="replaceable"
><I
>expr3</I
></TT
> is
    evaluated (executed).
   </P
><P
>&#13;    Each of the expressions can be empty.
    <TT
CLASS="replaceable"
><I
>expr2</I
></TT
> being empty means the loop should
    be run indefinitely (PHP implicitly considers it as
    <TT
CLASS="constant"
><B
>TRUE</B
></TT
>, like C).  This may not be as useless as
    you might think, since often you'd want to end the loop using a
    conditional <A
HREF="control-structures.break.html"
><TT
CLASS="literal"
>break</TT
></A
>
    statement instead of using the <TT
CLASS="literal"
>for</TT
> truth
    expression.
   </P
><P
>&#13;    Consider the following examples.  All of them display numbers from
    1 to 10:
    <DIV
CLASS="informalexample"
><A
NAME="AEN4941"
></A
><P
></P
><TABLE
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><TD
><PRE
CLASS="php"
>/* example 1 */

for ($i = 1; $i &#60;= 10; $i++) {
    print $i;
}

/* example 2 */

for ($i = 1;;$i++) {
    if ($i &#62; 10) {
        break;
    }
    print $i;
}

/* example 3 */

$i = 1;
for (;;) {
    if ($i &#62; 10) {
        break;
    }
    print $i;
    $i++;
}

/* example 4 */

for ($i = 1; $i &#60;= 10; print $i, $i++);</PRE
></TD
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><P
></P
></DIV
>
   </P
><P
>&#13;    Of course, the first example appears to be the nicest one (or
    perhaps the fourth), but you may find that being able to use empty
    expressions in <TT
CLASS="literal"
>for</TT
> loops comes in handy in many
    occasions.
   </P
><P
>&#13;    PHP also supports the alternate "colon syntax" for
    <TT
CLASS="literal"
>for</TT
> loops.
    <DIV
CLASS="informalexample"
><A
NAME="AEN4947"
></A
><P
></P
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><TD
><PRE
CLASS="programlisting"
>for (expr1; expr2; expr3): statement; ...; endfor;</PRE
></TD
></TR
></TABLE
><P
></P
></DIV
>
   </P
><P
>&#13;    Other languages have a <TT
CLASS="literal"
>foreach</TT
> statement to
    traverse an array or hash. PHP 3 has no such construct; PHP 4 does
    (see <A
HREF="control-structures.foreach.html"
>foreach</A
>). In PHP 3, you
    can combine <A
HREF="control-structures.while.html"
>while</A
>
    with the <A
HREF="function.list.html"
><B
CLASS="function"
>list()</B
></A
> and <A
HREF="function.each.html"
><B
CLASS="function"
>each()</B
></A
>
    functions to achieve the same effect. See the documentation for
    these functions for an example.
   </P
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