PHP身份证正则验证(兼容15，18位身份证)代码一例

<?php
/**
 * 身份证号码验证
 * site http://bbs.it-home.org
*/
function checkIdCard($idcard){
 if(empty($idcard)){
  return false;
 }
 $City = array(11=>"北京",12=>"天津",13=>"河北",14=>"山西",15=>"内蒙古",21=>"辽宁",22=>"吉林",23=>"黑龙江",31=>"上海",
32=>"江苏",33=>"浙江",34=>"安徽",35=>"福建",36=>"江西",37=>"山东",41=>"河南",42=>"湖北",43=>"湖南",44=>"广东",45=>"广西",
46=>"海南",50=>"重庆",51=>"四川",52=>"贵州",53=>"云南",54=>"西藏",61=>"陕西",62=>"甘肃",63=>"青海",64=>"宁夏",65=>"新疆",
71=>"台湾",81=>"香港",82=>"澳门",91=>"国外");
 $iSum = 0;
 $idCardLength = strlen($idcard);
 //长度验证
 if(!preg_match('/^\d{17}(\d|x)$/i',$idcard) and!preg_match('/^\d{15}$/i',$idcard))
 {
  return false;
 }
 //地区验证
 if(!array_key_exists(intval(substr($idcard,0,2)),$City))
 {
    return false;
 }
 // 15位身份证验证生日，转换为18位
 if ($idCardLength == 15)
 {
  $sBirthday = '19'.substr($idcard,6,2).'-'.substr($idcard,8,2).'-'.substr($idcard,10,2);
  $d = new DateTime($sBirthday);
  $dd = $d->format('Y-m-d');
  if($sBirthday != $dd)
  {
   return false;
  }
  $idcard = substr($idcard,0,6)."19".substr($idcard,6,9);//15to18
  $Bit18 = getVerifyBit($idcard);//算出第18位校验码
  $idcard = $idcard.$Bit18;
 }
 // 判断是否大于2078年，小于1900年
 $year = substr($idcard,6,4);
 if ($year<1900 || $year>2078 )
 {
  return false;
 }

 //18位身份证处理
 $sBirthday = substr($idcard,6,4).'-'.substr($idcard,10,2).'-'.substr($idcard,12,2);
 $d = new DateTime($sBirthday);
 $dd = $d->format('Y-m-d');
 if($sBirthday != $dd)
  {
  return false;
  }
 //身份证编码规范验证
 $idcard_base = substr($idcard,0,17);
 if(strtoupper(substr($idcard,17,1)) != getVerifyBit($idcard_base))
 {
  return false;
 }else{
  return true;
 }
}

// 计算身份证校验码，根据国家标准GB 11643-1999
function getVerifyBit($idcard_base)
{
 if(strlen($idcard_base) != 17)
 {
  return false;
 }
 //加权因子
 $factor = array(7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2);
 //校验码对应值
 $verify_number_list = array('1', '0', 'X', '9', '8', '7', '6', '5', '4','3', '2');
 $checksum = 0;
 for ($i = 0; $i < strlen($idcard_base); $i++)
 {
  $checksum += substr($idcard_base, $i, 1) * $factor[$i];
 }
 $mod = $checksum % 11;
 $verify_number = $verify_number_list[$mod];
 return $verify_number;
}
?>