函数封装——函数封装——函数封装

 身份证正则验证： 

 const pattern = /(^\d{8}(0\d|10|11|12)([0-2]\d|30|31)\d{3}$)|(^\d{6}(18|19|20)\d{2}(0\d|10|11|12)([0-2]\d|30|31)\d{3}(\d|X|x)$)/

根据身份证截取出生日期

<script>
      
    function getBirthdayFromIdCard (idCard) {
      var birthday = ''
      if (idCard != null && idCard !== '') {
        if (idCard.length === 15) {
          birthday = '19' + idCard.substr(6, 6)
        } else if (idCard.length === 18) {
          birthday = idCard.substr(6, 8)
        }
        birthday = birthday.replace(/(.{4})(.{2})/, '$1-$2-')
      }

      return birthday
    }
   console.log( getBirthdayFromIdCard('140321199909100911'));  //1999-09-10
   
</script>