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<?php<br />
$arr = array(<br />
	0 => array('id'=>12,'name'=>'NO.1'),<br />
	1 => array('id'=>13,'name'=>'NO.2'),<br />
);<br />
<br />
$_check_id = 0;<br />
if($arr) {<br />
foreach($arr as $v){<br />
?><br />
<input type="radio" name="c" id="d_<?php echo $v['id']?>" value="<?php echo $v[id]?>" /><?php echo $v['name']?><br><br />
<?php <br />
}<br />
}?>

<br />
<br />
	$arr = array(<br />
    0 => array('id'=>12,'name'=>'NO.1'),<br />
    1 => array('id'=>13,'name'=>'NO.2'),<br />
    2 => array('id'=>14,'name'=>'NO.3'),<br />
    3 => array('id'=>15,'name'=>'NO.4'),<br />
	);<br />
	<br />
	$_check_id = 14;<br />
	$found = false;<br />
	$htmls = array();<br />
	if($arr) {<br />
		foreach($arr as $v){<br />
			$input_pre = <<<EOT<br />
				<input type="radio" name="c" id="d_{$v['id']}" value="{$v['id']}"<br />
EOT;<br />
			$input_post = <<<EOT<br />
				/>{$v['name']}<br />
EOT;<br />
			if(!$found && $_check_id == $v['id']) {<br />
				$found = true;<br />
				$input_pre .= ' checked ';<br />
			}<br />
			$htmls[] = array($input_pre, $input_post);<br />
		}<br />
	}<br />
	$htmlstr = '';<br />
	foreach($htmls as $html) {<br />
		if(!$found) {<br />
			$html[0] .= ' checked ';<br />
			$found = true;<br />
		}<br />
		$htmlstr .= implode('', $html);<br />
	}<br />
	echo $htmlstr;<br />

<?php<br />
$arr = array(<br />
    0 => array('id'=>12,'name'=>'NO.1'),<br />
    1 => array('id'=>13,'name'=>'NO.2'),<br />
    2 => array('id'=>14,'name'=>'NO.3'),<br />
);<br />
 <br />
$_check_id = 0;<br />
if($arr) {<br />
  foreach($arr as &$v) {<br />
    if($_check_id == $v['id']) {<br />
      $v['check'] = ' checked';<br />
      $_check_id = -1;<br />
    }<br />
  }<br />
  if($_check_id >=0) $arr[0]['check'] = ' checked';<br />
  foreach($arr as $v){<br />
?><br />
<input type="radio" name="c" id="d_<?php echo $v['id']?>" value="<?php echo $v['id']?>" <?php ;echo isset($v['check'])?$v['check']:''?> /><?php echo $v['name']?><br />
<?php <br />
}<br />
}?>

<br />
foreach($arr as $key=>$v){<br />
	if($key == $_check_id){<br />
	//这儿是checked<br />
	continue;<br />
	}<br />
......<br />