foreach多层嵌套的问题，求解~！
<br /><?php <br /> $a1=explode(',','20,21');<br /> $b1=explode(',','20,21');<br /> $c1=explode(',','20,21');<br /> $d1=explode(',','20,21');<br /> $e1=explode(',','20,21');<br /> foreach($a1 as $a ){<br /> <br /> foreach($b1 as $b){<br /><br /> foreach($c1 as $c){<br /> <br /> foreach($d1 as $d){ <br /><br /> foreach($e1 as $e){ <br /> <br /> }<br /> <br /> }<br /> <br /> }<br /><br /><br /> }<br /> <br /> }<br />?><br /><br /> foreach($a1 as $a ){<br /> echo $a;<br /> }<br /> foreach($b1 as $b ){<br /> echo $b;<br /> }<br />
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