支持15和18位

 function isIdCard(idcard) {
    idcard = idcard.toUpperCase()
    let regx = /(^\d{15}$)|(^\d{17}([0-9]|X)$)/

    if (regx.test(idcard) === false) {
      return false;
    }
    //检查15位
    if (idcard.length == 15) {
      regx = /^(\d{6})+(\d{2})+(\d{2})+(\d{2})+(\d{3})$/;
      let arr_split = idcard.match(regx)
      let dtm_birth = "19" + arr_split[2] + '-' + arr_split[3] + '-' + arr_split[4];
      if (isNaN(dtm_birth) && !isNaN(Date.parse(dtm_birth))) {
        return true;
      } else {
        return false;
      }
    } else {
      //检查18位
      regx = /^(\d{6})+(\d{4})+(\d{2})+(\d{2})+(\d{3})([0-9]|X)$/;
      let arr_split = idcard.match(regx)
      let dtm_birth = arr_split[2] + '/' + arr_split[3] + '/' + arr_split[4];
      //检查生日日期是否正确
      if (isNaN(dtm_birth) && !isNaN(Date.parse(dtm_birth))) {
        //检验18位身份证的校验码是否正确。 校验位按照ISO 7064:1983.MOD 11-2的规定生成，X可以认为是数字10。
        let arr_int = [7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2]
        let arr_ch = ['1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2']
        let sign = 0;
        for (let index = 0; index < 17; index++) {
          let b = idcard[index] * 1;
          let w = arr_int[index];
          sign += b * w;
        }
        let n = sign % 11;
        let val_num = arr_ch[n];
        if (val_num != idcard.substr(17, 1)) {
          return false;
        } else {
          return true;
        }
      } else {
        return false
      }
    }
  }
[/prism]