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>while</VAR
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><P
> <VAR
CLASS="literal"
>while</VAR
> loops are the simplest type of loop in
PHP. They behave just like their C counterparts. The basic form
of a <VAR
CLASS="literal"
>while</VAR
> statement is:
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><PRE
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>while (expr) statement</PRE
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>
</P
><P
> The meaning of a <VAR
CLASS="literal"
>while</VAR
> statement is simple. It
tells PHP to execute the nested statement(s) repeatedly, as long
as the <VAR
CLASS="literal"
>while</VAR
> expression evaluates to
<TT
CLASS="constant"
><B
>TRUE</B
></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
<VAR
CLASS="literal"
>while</VAR
> expression evaluates to
<TT
CLASS="constant"
><B
>FALSE</B
></TT
> from the very beginning, the nested
statement(s) won't even be run once.
</P
><P
> Like with the <VAR
CLASS="literal"
>if</VAR
> statement, you can group
multiple statements within the same <VAR
CLASS="literal"
>while</VAR
> loop
by surrounding a group of statements with curly braces, or by
using the alternate syntax:
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><PRE
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>while (expr): statement ... endwhile;</PRE
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>
</P
><P
> The following examples are identical, and both print numbers from
1 to 10:
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><code><font color="#000000">
<font color="#0000BB"><?php<br /></font><font color="#FF8000">/* example 1 */<br /><br /></font><font color="#0000BB">$i </font><font color="#007700">= </font><font color="#0000BB">1</font><font color="#007700">;<br />while (</font><font color="#0000BB">$i </font><font color="#007700"><= </font><font color="#0000BB">10</font><font color="#007700">) {<br /> echo </font><font color="#0000BB">$i</font><font color="#007700">++; </font><font color="#FF8000">/* the printed value would be<br /> $i before the increment<br /> (post-increment) */<br /></font><font color="#007700">}<br /><br /></font><font color="#FF8000">/* example 2 */<br /><br /></font><font color="#0000BB">$i </font><font color="#007700">= </font><font color="#0000BB">1</font><font color="#007700">;<br />while (</font><font color="#0000BB">$i </font><font color="#007700"><= </font><font color="#0000BB">10</font><font color="#007700">):<br /> echo </font><font color="#0000BB">$i</font><font color="#007700">;<br /> </font><font color="#0000BB">$i</font><font color="#007700">++;<br />endwhile;<br /></font><font color="#0000BB">?></font>
</font>
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