废话不多说，上代码：
?
function ishuiwen($str)
{
$l = 1;
//全是中文
if (preg_match("/^[\x7f-\xff]+$/", $str)) {
$len = mb_strlen($str);
$k = intval($len / 2) + 1;
for ($j = 0; $j < $k; $j++) {
if (substr($str, 3 * $j, 3) != substr($str, -(3 * ($j + 1)), 3)) {
$l = 0;
break;
}
}
} //全不是中文
else {
$len = strlen($str);
$k = intval($len / 2) + 1;
for ($j = 0; $j < $k; $j++) {
if (substr($str, $j, 1) != substr($str, $len - $j - 1, 1)) {
$l = 0;
break;
}
}
}
if ($l == 1) {
return true;
} else {
return false;
}
}
//$str = '上海自来水来自海上';
//$str = '12321';
$str = 789987;
var_dump(ishuiwen($str));
