JavaScript method to randomly generate credit card numbers

JavaScript method to randomly generate credit card numbers_javascript skills

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Release： 2016-05-16 16:05:13

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The example in this article describes how to randomly generate credit card numbers using JavaScript. Share it with everyone for your reference. The specific analysis is as follows:

This JS code randomly generates credit card numbers according to the credit card number generation rules. It can be verified and is for learning reference only. Please do not use it for illegal purposes, otherwise you will be responsible for the consequences.

var visaPrefixList = new Array(
 "4539",
 "4556",
 "4916",
 "4532",
 "4929",
 "40240071",
 "4485",
 "4716",
 "4"
);
var mastercardPrefixList = new Array(
 "51",
 "52",
 "53",
 "54",
 "55"
);
var amexPrefixList = new Array(
 "34",
 "37"
);
var discoverPrefixList = new Array("6011");
var dinersPrefixList = new Array(
 "300",
 "301",
 "302",
 "303",
 "36",
 "38"
);
var enRoutePrefixList = new Array(
 "2014",
 "2149"
);
var jcbPrefixList = new Array(
 "35"
);
var voyagerPrefixList = new Array("8699");
function strrev(str) {
  if (!str) return '';
  var revstr='';
  for (i = str.length-1; i>=0; i--)
   revstr+=str.charAt(i)
  return revstr;
}
/*
'prefix' is the start of the CC number as a string, 
any number of digits.
'length' is the length of the CC number to generate. 
Typically 13 or 16
*/
function completed_number(prefix, length) {
 var ccnumber = prefix;
 // generate digits
 while ( ccnumber.length < (length - 1) ) {
  ccnumber += Math.floor(Math.random()*10);
 }
 // reverse number and convert to int
 var reversedCCnumberString = strrev( ccnumber );
 var reversedCCnumber = new Array();
 for ( var i=0; i < reversedCCnumberString.length; i++ ) {
  reversedCCnumber[i] = parseInt(reversedCCnumberString.charAt(i));
 }
 // calculate sum
 var sum = 0;
 var pos = 0;
 while ( pos < length - 1 ) {
  odd = reversedCCnumber[ pos ] * 2;
  if ( odd > 9 ) {
   odd -= 9;
  }
  sum += odd;
  if ( pos != (length - 2) ) {
 
   sum += reversedCCnumber[ pos +1 ];
  }
  pos += 2;
 }
 // calculate check digit
 var checkdigit = ((Math.floor(sum/10)+1)*10-sum)%10;
 ccnumber += checkdigit;
 return ccnumber;
}
function credit_card_number(prefixList, length, howMany) {
 var result = new Array();
 for (var i = 0; i < howMany; i++) {
  var randomArrayIndex = Math.floor(Math.random() * 
 prefixList.length);
  var ccnumber = prefixList[ randomArrayIndex ];
  result.push( completed_number(ccnumber, length) );
 }
 return result;
}

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Calling method:

Save the above code as gencc.js file

<html>
<head>
<script src="gencc.js" type="text/javascript"></script>
</head>
<body>
<h3>VISA:</h3>
<script>
var visa = credit_card_number(visaPrefixList, 16, 3);
document.write( visa );
</script>
<h3>Amex:</h3>
<script>
var amex = credit_card_number(amexPrefixList, 15, 3);
document.write( amex );
</script>
</body>
</html>

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I hope this article will be helpful to everyone’s JavaScript programming design.