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NAME="control-structures.while"
><TT
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>while</TT
></A
></H1
><P
>&#13;    <TT
CLASS="literal"
>while</TT
> loops are the simplest type of loop in
    PHP.  They behave just like their C counterparts.  The basic form
    of a <TT
CLASS="literal"
>while</TT
> statement is:
    <DIV
CLASS="informalexample"
><A
NAME="AEN3408"
></A
><P
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><PRE
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>&#13;while (expr) statement
     </PRE
></TD
></TR
></TABLE
><P
></P
></DIV
>
   </P
><P
>&#13;    The meaning of a <TT
CLASS="literal"
>while</TT
> statement is simple.  It
    tells PHP to execute the nested statement(s) repeatedly, as long
    as the <TT
CLASS="literal"
>while</TT
> expression evaluates to
    <TT
CLASS="literal"
>TRUE</TT
>.  The value of the expression is checked
    each time at the beginning of the loop, so even if this value
    changes during the execution of the nested statement(s), execution
    will not stop until the end of the iteration (each time PHP runs
    the statements in the loop is one iteration).  Sometimes, if the
    <TT
CLASS="literal"
>while</TT
> expression evaluates to
    <TT
CLASS="literal"
>FALSE</TT
> from the very beginning, the nested
    statement(s) won't even be run once.
   </P
><P
>&#13;    Like with the <TT
CLASS="literal"
>if</TT
> statement, you can group
    multiple statements within the same <TT
CLASS="literal"
>while</TT
> loop
    by surrounding a group of statements with curly braces, or by
    using the alternate syntax:
    <DIV
CLASS="informalexample"
><A
NAME="AEN3419"
></A
><P
></P
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><PRE
CLASS="programlisting"
>&#13;while (expr): statement ... endwhile;
     </PRE
></TD
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><P
></P
></DIV
>
   </P
><P
>&#13;    The following examples are identical, and both print numbers from
    1 to 10:
    <DIV
CLASS="informalexample"
><A
NAME="AEN3422"
></A
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></P
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><PRE
CLASS="programlisting"
>&#13;/* example 1 */

$i = 1;
while ($i &#60;= 10) {
    print $i++;  /* the printed value would be
                    $i before the increment
                    (post-increment) */
}
 
/* example 2 */
 
$i = 1;
while ($i &#60;= 10):
    print $i;
    $i++;
endwhile;
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