Use regular expressions to verify the bank card number entered by the user (with code)

This time I will bring you the use of regex to verify the bank card number entered by the user (with code). What are the precautions for using the regex to verify the bank card number entered by the user. The following is a practical case. Let’s take a look. .

//JS regular implementation of the control and formatting of user input bank card numbers

<script language="javascript" type="text/javascript">
function formatBankNo (BankNo){
  if (BankNo.value == "") return;
  var account = new String (BankNo.value);
  account = account.substring(0,22); /*帐号的总数, 包括空格在内 */
  if (account.match (".[0-9]{4}-[0-9]{4}-[0-9]{4}-[0-9]{7}") == null){
    /* 对照格式 */
    if (account.match (".[0-9]{4}-[0-9]{4}-[0-9]{4}-[0-9]{7}|" + ".[0-9]{4}-[0-9]{4}-[0-9]{4}-[0-9]{7}|" +
    ".[0-9]{4}-[0-9]{4}-[0-9]{4}-[0-9]{7}|" + ".[0-9]{4}-[0-9]{4}-[0-9]{4}-[0-9]{7}") == null){
      var accountNumeric = accountChar = "", i;
      for (i=0;i<account.length;i++){
        accountChar = account.substr (i,1);
        if (!isNaN (accountChar) && (accountChar != " ")) accountNumeric = accountNumeric + accountChar;
      }
      account = "";
      for (i=0;i<accountNumeric.length;i++){  /* 可将以下空格改为-,效果也不错 */
        if (i == 4) account = account + " "; /* 帐号第四位数后加空格 */
        if (i == 8) account = account + " "; /* 帐号第八位数后加空格 */
        if (i == 12) account = account + " ";/* 帐号第十二位后数后加空格 */
        account = account + accountNumeric.substr (i,1)
      }
    }
  }
  else
  {
    account = " " + account.substring (1,5) + " " + account.substring (6,10) + " " + account.substring (14,18) + "-" + account.substring(18,25);
  }
  if (account != BankNo.value) BankNo.value = account;
}
</script>

<input type="text" value="" size="25" onkeyup="formatBankNo(this)" onkeydown="formatBankNo(this)" name="account" id="account">

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the PHP Chinese website!

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